/*
 This file is part of Konsole, a terminal emulator for KDE.

 Copyright 2006-2008 by Robert Knight <robertknight@gmail.com>
 Copyright 1997,1998 by Lars Doelle <lars.doelle@on-line.de>

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 02110-1301  USA.
*/
#include "TerminalDisplay.h"

#include <QAbstractButton>
#include <QApplication>
#include <QBoxLayout>
#include <QClipboard>
#include <QDrag>
#include <QEvent>
#include <QFile>
#include <QGridLayout>
#include <QKeyEvent>
#include <QLabel>
#include <QLayout>
#include <QMediaPlayer>
#include <QMessageBox>
#include <QMimeData>
#include <QMovie>
#include <QPainter>
#include <QPixmap>
#include <QRegularExpression>
#include <QStyle>
#include <QTime>
#include <QTimer>
#include <QToolTip>
#include <QUrl>
#include <QVideoFrame>
#include <QVideoSink>
#include <QtDebug>

#include "Filter.h"
#include "ScreenWindow.h"
#include "TerminalCharacterDecoder.h"

#ifndef loc
#define loc(X, Y) ((Y) * _columns + (X))
#endif

#define yMouseScroll 1

#define REPCHAR                                                                  \
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                                                 \
    "abcdefgjijklmnopqrstuvwxyz"                                                 \
    "0123456789./+@"

const ColorEntry base_color_table[TABLE_COLORS] =
// The following are almost IBM standard color codes, with some slight
// gamma correction for the dim colors to compensate for bright X screens.
// It contains the 8 ansiterm/xterm colors in 2 intensities.
{
    // Fixme: could add faint colors here, also.
    // normal
    ColorEntry(QColor(0x00, 0x00, 0x00), false),
    ColorEntry(QColor(0xB2, 0xB2, 0xB2), true), // Dfore, Dback
    ColorEntry(QColor(0x00, 0x00, 0x00), false),
    ColorEntry(QColor(0xB2, 0x18, 0x18), false), // Black, Red
    ColorEntry(QColor(0x18, 0xB2, 0x18), false),
    ColorEntry(QColor(0xB2, 0x68, 0x18), false), // Green, Yellow
    ColorEntry(QColor(0x18, 0x18, 0xB2), false),
    ColorEntry(QColor(0xB2, 0x18, 0xB2), false), // Blue, Magenta
    ColorEntry(QColor(0x18, 0xB2, 0xB2), false),
    ColorEntry(QColor(0xB2, 0xB2, 0xB2), false), // Cyan, White
    // intensiv
    ColorEntry(QColor(0x00, 0x00, 0x00), false),
    ColorEntry(QColor(0xFF, 0xFF, 0xFF), true),
    ColorEntry(QColor(0x68, 0x68, 0x68), false),
    ColorEntry(QColor(0xFF, 0x54, 0x54), false),
    ColorEntry(QColor(0x54, 0xFF, 0x54), false),
    ColorEntry(QColor(0xFF, 0xFF, 0x54), false),
    ColorEntry(QColor(0x54, 0x54, 0xFF), false),
    ColorEntry(QColor(0xFF, 0x54, 0xFF), false),
    ColorEntry(QColor(0x54, 0xFF, 0xFF), false),
    ColorEntry(QColor(0xFF, 0xFF, 0xFF), false)
};

// scroll increment used when dragging selection at top/bottom of window.

// static
bool TerminalDisplay::_antialiasText = true;

// we use this to force QPainter to display text in LTR mode
// more information can be found in: http://unicode.org/reports/tr9/
const QChar LTR_OVERRIDE_CHAR(0x202D);

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                Colors                                     */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/*  Note that we use ANSI color order (bgr), while IBMPC color order is (rgb)

    Code        0       1       2       3       4       5       6       7
    ----------- ------- ------- ------- ------- ------- ------- ------- -------
    ANSI  (bgr) Black   Red     Green   Yellow  Blue    Magenta Cyan    White
    IBMPC (rgb) Black   Blue    Green   Cyan    Red     Magenta Yellow  White
*/

// using global statics for the unclutter feature makes tracking the override cursor simple
// there's only one cursor to override and only one terminal relevant for that at any time
// gs_deadSpot serves as flag and also allows a position check - it doesn't matter that this isn't
// correct when checking the position across instances as its only purpose is to catch judder when
// the user doesn't really touch the mouse - once the mouse moves we'll quickly be out of the deadzone
static QPoint gs_deadSpot(-1,-1);
static QPoint gs_futureDeadSpot;
std::shared_ptr<QTimer> TerminalDisplay::_hideMouseTimer;

ScreenWindow *TerminalDisplay::screenWindow() const { return _screenWindow; }
void TerminalDisplay::setScreenWindow(ScreenWindow *window) {
    // disconnect existing screen window if any
    if (_screenWindow) {
        disconnect(_screenWindow, nullptr, this, nullptr);
    }

    _screenWindow = window;

    if (window) {
        // TODO: Determine if this is an issue.
        // #warning "The order here is not specified - does it matter whether
        // updateImage or updateLineProperties comes first?"
        connect(_screenWindow, &ScreenWindow::outputChanged, this,
                        &TerminalDisplay::updateLineProperties);
        connect(_screenWindow, &ScreenWindow::outputChanged, this,
                        &TerminalDisplay::updateImage);
        connect(_screenWindow, &ScreenWindow::outputChanged, this,
                        &TerminalDisplay::updateFilters);
        connect(_screenWindow, &ScreenWindow::scrolled, this,
                        &TerminalDisplay::updateFilters);
        connect(_screenWindow, &ScreenWindow::scrollToEnd, this,
                        &TerminalDisplay::scrollToEnd);
        connect(_screenWindow, &ScreenWindow::handleCtrlC, this,
                        &TerminalDisplay::handleCtrlC);
        window->setWindowLines(_lines);
    }
}

const ColorEntry *TerminalDisplay::colorTable() const { return _colorTable; }

void TerminalDisplay::setBackgroundColor(const QColor &color) {
    _colorTable[DEFAULT_BACK_COLOR].color = color;
    QPalette p = palette();
    p.setColor(backgroundRole(), color);
    setPalette(p);

    // Avoid propagating the palette change to the scroll bar
    _scrollBar->setPalette(QApplication::palette());

    update();
}

void TerminalDisplay::setForegroundColor(const QColor &color) {
    _colorTable[DEFAULT_FORE_COLOR].color = color;

    update();
}

void TerminalDisplay::setColorTableColor(const int colorId, const QColor &color) {
    _colorTable[colorId].color = color;
    update();
}

void TerminalDisplay::setColorTable(const ColorEntry table[]) {
    for (int i = 0; i < TABLE_COLORS; i++)
        _colorTable[i] = table[i];

    setBackgroundColor(_colorTable[DEFAULT_BACK_COLOR].color);
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                                   Font                                    */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/*
 The VT100 has 32 special graphical characters. The usual vt100 extended
 xterm fonts have these at 0x00..0x1f.
 
 QT's iso mapping leaves 0x00..0x7f without any changes. But the graphicals
 come in here as proper unicode characters.
 
 We treat non-iso10646 fonts as VT100 extended and do the required mapping
 from unicode to 0x00..0x1f. The remaining translation is then left to the
 QCodec.
*/

bool TerminalDisplay::isLineChar(Character c) const {
    return _drawLineChars && c.isLineChar();
}

bool TerminalDisplay::isLineCharString(const std::wstring& string) const {
    return string.length() > 0 && _drawLineChars && (string[0] & 0xFF80) == 0x2500;
}

void TerminalDisplay::fontChange(const QFont &) {
    QFontMetrics fm(font());
    _fontHeight = fm.height() + _lineSpacing;

    // waba TerminalDisplay 1.123:
    // "Base character width on widest ASCII character. This prevents too wide
    //  characters in the presence of double wide (e.g. Japanese) characters."
    // Get the width from representative normal width characters
    _fontWidth = qRound((double)fm.horizontalAdvance(QLatin1String(REPCHAR)) /
                                            (double)qstrlen(REPCHAR));

    _fixedFont = true;

    int fw = fm.horizontalAdvance(QLatin1Char(REPCHAR[0]));
    for (unsigned int i = 1; i < qstrlen(REPCHAR); i++) {
        if (fw != fm.horizontalAdvance(QLatin1Char(REPCHAR[i]))) {
            _fixedFont = false;
            break;
        }
    }

    _fixedFont_original = _fixedFont;

    if (_fontWidth < 1)
        _fontWidth = 1;

    _fontAscent = fm.ascent();

    emit changedFontMetricSignal(_fontHeight, _fontWidth);
    propagateSize();

    // We will run paint event testing procedure.
    // Although this operation will destroy the original content,
    // the content will be drawn again after the test.
    _drawTextTestFlag = true;
    update();
}

void TerminalDisplay::calDrawTextAdditionHeight(QPainter &painter) {
    QRect test_rect, feedback_rect;
    test_rect.setRect(1, 1, _fontWidth * 4, _fontHeight);
    painter.save();
    painter.setOpacity(0);
    painter.drawText(test_rect, Qt::AlignBottom,
                                     LTR_OVERRIDE_CHAR + QLatin1String("Mq"), &feedback_rect);

    // qDebug() << "test_rect:" << test_rect << "feeback_rect:" << feedback_rect;
    painter.restore();

    _drawTextAdditionHeight = qMax(0, (feedback_rect.height() - _fontHeight) / 2);

    _drawTextTestFlag = false;
}

void TerminalDisplay::setVTFont(const QFont &f) {
    QFont font = f;

    // Check if font is not fixed pitch and print a warning
    if (!QFontInfo(font).fixedPitch()) {
        // qDebug() << "Using a variable-width font in the terminal.  This may cause
        // performance degradation and display/alignment errors.";
    }

    // hint that text should be drawn without anti-aliasing.
    // depending on the user's font configuration, this may not be respected
    if (!_antialiasText)
        font.setStyleStrategy(QFont::NoAntialias);

    // experimental optimization.  Konsole assumes that the terminal is using a
    // mono-spaced font, in which case kerning information should have no effect.
    // Disabling kerning saves some computation when rendering text.
    font.setKerning(false);

    // QFont::ForceIntegerMetrics has been removed.
    // Set full hinting instead to ensure the letters are aligned properly.
    font.setHintingPreference(QFont::PreferFullHinting);

    // "Draw intense colors in bold font" feature needs to use different font
    // weights. StyleName property, when set, doesn't allow weight changes. Since
    // all properties (weight, stretch, italic, etc) are stored in QFont
    // independently, in almost all cases styleName is not needed.
    font.setStyleName(QString());

    QWidget::setFont(font);
    _charWidth->setFont(font);
    fontChange(font);
}

void TerminalDisplay::setFont(const QFont &) {
    // ignore font change request if not coming from konsole itself
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                         Constructor / Destructor                          */
/*                                                                           */
/* ------------------------------------------------------------------------- */

TerminalDisplay::TerminalDisplay(QWidget *parent)
        : QWidget(parent), _screenWindow(nullptr), _allowBell(true),
        _gridLayout(nullptr), _fontHeight(1), _fontWidth(1), _fontAscent(1),
        _boldIntense(true), _lines(1), _columns(1), _usedLines(1),
        _usedColumns(1), _contentHeight(1), _contentWidth(1), _image(nullptr),
        _resizing(false), _terminalSizeHint(false), _terminalSizeStartup(true),
        _bidiEnabled(true), _mouseMarks(false), _isPrimaryScreen(true),
        _disabledBracketedPasteMode(false), _showResizeNotificationEnabled(true),
        _actSel(0), _wordSelectionMode(false), _lineSelectionMode(false),
        _preserveLineBreaks(false), _columnSelectionMode(false),
        _scrollbarLocation(QTermWidget::NoScrollBar),
        _wordCharacters(QLatin1String(":@-./_~")), _bellMode(SystemBeepBell),
        _blinking(false), _hasBlinker(false), _cursorBlinking(false),
        _hasBlinkingCursor(false), _allowBlinkingText(true), _ctrlDrag(false),
        _tripleClickMode(SelectWholeLine), _isFixedSize(false),
        _possibleTripleClick(false), _resizeWidget(nullptr),
        _resizeTimer(nullptr), _flowControlWarningEnabled(false),
        _outputSuspendedLabel(nullptr), _lineSpacing(0), _colorsInverted(false),
        _opacity(static_cast<qreal>(1)), _backgroundMode(None),
        _selectedTextOpacity(static_cast<qreal>(1)),
        _filterChain(new TerminalImageFilterChain()),
        _cursorShape(Emulation::KeyboardCursorShape::BlockCursor),
        mMotionAfterPasting(NoMoveScreenWindow), _leftBaseMargin(1),
        _topBaseMargin(1), _drawLineChars(true),_mouseAutohideDelay(-1) {
    // variables for draw text
    _drawTextAdditionHeight = 0;
    _drawTextTestFlag = false;

    // terminal applications are not designed with Right-To-Left in mind,
    // so the layout is forced to Left-To-Right
    setLayoutDirection(Qt::LeftToRight);

    // The offsets are not yet calculated.
    // Do not calculate these too often to be more smoothly when resizing
    // konsole in opaque mode.
    _topMargin = _topBaseMargin;
    _leftMargin = _leftBaseMargin;

    // create scroll bar for scrolling output up and down
    // set the scroll bar's slider to occupy the whole area of the scroll bar
    // initially
    _scrollBar = new ScrollBar(this);
    QString style_sheet = qApp->styleSheet();
    _scrollBar->setStyleSheet(style_sheet);
    // since the contrast with the terminal background may not be enough,
    // the scrollbar should be auto-filled if not transient
    if (!_scrollBar->style()->styleHint(QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
        _scrollBar->setAutoFillBackground(true);
    setScroll(0, 0);
    _scrollBar->setCursor(Qt::ArrowCursor);
    connect(_scrollBar, &QScrollBar::valueChanged, this,
                    &TerminalDisplay::scrollBarPositionChanged);
    // qtermwidget: we have to hide it here due the
    // _scrollbarLocation==NoScrollBar check in
    // TerminalDisplay::setScrollBarPosition(ScrollBarPosition position)
    _scrollBar->hide();

    // setup timers for blinking cursor and text
    _blinkTimer = new QTimer(this);
    connect(_blinkTimer, &QTimer::timeout, this, &TerminalDisplay::blinkEvent);
    _blinkCursorTimer = new QTimer(this);
    connect(_blinkCursorTimer, &QTimer::timeout, this,
                    &TerminalDisplay::blinkCursorEvent);

    setUsesMouse(true);
    setBracketedPasteMode(false);
    setColorTable(base_color_table);
    setMouseTracking(true);

    // Enable drag and drop
    setAcceptDrops(true); // attempt
    dragInfo.state = diNone;

    setFocusPolicy(Qt::WheelFocus);

    // enable input method support
    setAttribute(Qt::WA_InputMethodEnabled, true);
    setInputMethodHints(Qt::ImhSensitiveData | Qt::ImhNoAutoUppercase |
                                            Qt::ImhNoPredictiveText | Qt::ImhMultiLine);

    // this is an important optimization, it tells Qt
    // that TerminalDisplay will handle repainting its entire area.
    setAttribute(Qt::WA_OpaquePaintEvent);

    _gridLayout = new QGridLayout(this);
    _gridLayout->setContentsMargins(0, 0, 0, 0);

    setLayout(_gridLayout);

    _charWidth = new CharWidth(font());

    _isLocked = false;
    _lockbackgroundImage = QPixmap(10, 10);
    _lockbackgroundImage.fill(Qt::gray);

    _backgroundVideoPlayer = new QMediaPlayer;
    _backgroundVideoSink = new QVideoSink;
    _backgroundVideoPlayer->setLoops(QMediaPlayer::Infinite);
    _backgroundVideoPlayer->setVideoOutput(_backgroundVideoSink);
    connect(_backgroundVideoSink, &QVideoSink::videoFrameChanged, this, [&](const QVideoFrame &frame) {
        _backgroundVideoFrame = QPixmap::fromImage(frame.toImage());
        update();
    });

    new AutoScrollHandler(this);
}

TerminalDisplay::~TerminalDisplay() {
    if (_backgroundVideoPlayer->isPlaying()) {
        _backgroundVideoPlayer->stop();
    }
    delete _backgroundVideoPlayer;
    delete _backgroundVideoSink;
    if (_backgroundMovie != nullptr) {
        _backgroundMovie->stop();
        QObject::disconnect(_backgroundMovie, nullptr, this, nullptr);
        delete _backgroundMovie;
    }
    disconnect(_blinkTimer);
    disconnect(_blinkCursorTimer);
    if (_hideMouseTimer)
        disconnect(_hideMouseTimer.get());
    qApp->removeEventFilter(this);

    delete[] _image;

    delete _charWidth;
    delete _gridLayout;
    delete _outputSuspendedLabel;
    delete _filterChain;
}

/* ------------------------------------------------------------------------- */
/*                                                                           */
/*                             Display Operations                            */
/*                                                                           */
/* ------------------------------------------------------------------------- */

/**
 A table for emulating the simple (single width) unicode drawing chars.
 It represents the 250x - 257x glyphs. If it's zero, we can't use it.
 if it's not, it's encoded as follows: imagine a 5x5 grid where the points are
 numbered 0 to 24 left to top, top to bottom. Each point is represented by the
 corresponding bit.

 Then, the pixels basically have the following interpretation:
 _|||_
 -...-
 -...-
 -...-
 _|||_

 where _ = none
      | = vertical line.
      - = horizontal line.
 */

enum LineEncode {
    TopL = (1 << 1),
    TopC = (1 << 2),
    TopR = (1 << 3),

    LeftT = (1 << 5),
    Int11 = (1 << 6),
    Int12 = (1 << 7),
    Int13 = (1 << 8),
    RightT = (1 << 9),

    LeftC = (1 << 10),
    Int21 = (1 << 11),
    Int22 = (1 << 12),
    Int23 = (1 << 13),
    RightC = (1 << 14),

    LeftB = (1 << 15),
    Int31 = (1 << 16),
    Int32 = (1 << 17),
    Int33 = (1 << 18),
    RightB = (1 << 19),

    BotL = (1 << 21),
    BotC = (1 << 22),
    BotR = (1 << 23)
};

static const quint32 LineChars[] = {
    0x00007c00, 0x000fffe0, 0x00421084, 0x00e739ce, 0x00000000, 0x00000000,
    0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    0x00427000, 0x004e7380, 0x00e77800, 0x00ef7bc0, 0x00421c00, 0x00439ce0,
    0x00e73c00, 0x00e7bde0, 0x00007084, 0x000e7384, 0x000079ce, 0x000f7bce,
    0x00001c84, 0x00039ce4, 0x00003dce, 0x0007bdee, 0x00427084, 0x004e7384,
    0x004279ce, 0x00e77884, 0x00e779ce, 0x004f7bce, 0x00ef7bc4, 0x00ef7bce,
    0x00421c84, 0x00439ce4, 0x00423dce, 0x00e73c84, 0x00e73dce, 0x0047bdee,
    0x00e7bde4, 0x00e7bdee, 0x00427c00, 0x0043fce0, 0x004e7f80, 0x004fffe0,
    0x004fffe0, 0x00e7fde0, 0x006f7fc0, 0x00efffe0, 0x00007c84, 0x0003fce4,
    0x000e7f84, 0x000fffe4, 0x00007dce, 0x0007fdee, 0x000f7fce, 0x000fffee,
    0x00427c84, 0x0043fce4, 0x004e7f84, 0x004fffe4, 0x00427dce, 0x00e77c84,
    0x00e77dce, 0x0047fdee, 0x004e7fce, 0x00e7fde4, 0x00ef7f84, 0x004fffee,
    0x00efffe4, 0x00e7fdee, 0x00ef7fce, 0x00efffee, 0x00000000, 0x00000000,
    0x00000000, 0x00000000, 0x000f83e0, 0x00a5294a, 0x004e1380, 0x00a57800,
    0x00ad0bc0, 0x004390e0, 0x00a53c00, 0x00a5a1e0, 0x000e1384, 0x0000794a,
    0x000f0b4a, 0x000390e4, 0x00003d4a, 0x0007a16a, 0x004e1384, 0x00a5694a,
    0x00ad2b4a, 0x004390e4, 0x00a52d4a, 0x00a5a16a, 0x004f83e0, 0x00a57c00,
    0x00ad83e0, 0x000f83e4, 0x00007d4a, 0x000f836a, 0x004f93e4, 0x00a57d4a,
    0x00ad836a, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    0x00000000, 0x00000000, 0x00001c00, 0x00001084, 0x00007000, 0x00421000,
    0x00039ce0, 0x000039ce, 0x000e7380, 0x00e73800, 0x000e7f80, 0x00e73884,
    0x0003fce0, 0x004239ce
};

static void drawLineChar(QPainter &paint, int x, int y, int w, int h, uint8_t code) {
    // Calculate cell midpoints, end points.
    int cx = x + w / 2;
    int cy = y + h / 2;
    int ex = x + w - 1;
    int ey = y + h - 1;

    quint32 toDraw = LineChars[code];

    // Top _lines:
    if (toDraw & TopL)
        paint.drawLine(cx - 1, y, cx - 1, cy - 2);
    if (toDraw & TopC)
        paint.drawLine(cx, y, cx, cy - 2);
    if (toDraw & TopR)
        paint.drawLine(cx + 1, y, cx + 1, cy - 2);

    // Bot _lines:
    if (toDraw & BotL)
        paint.drawLine(cx - 1, cy + 2, cx - 1, ey);
    if (toDraw & BotC)
        paint.drawLine(cx, cy + 2, cx, ey);
    if (toDraw & BotR)
        paint.drawLine(cx + 1, cy + 2, cx + 1, ey);

    // Left _lines:
    if (toDraw & LeftT)
        paint.drawLine(x, cy - 1, cx - 2, cy - 1);
    if (toDraw & LeftC)
        paint.drawLine(x, cy, cx - 2, cy);
    if (toDraw & LeftB)
        paint.drawLine(x, cy + 1, cx - 2, cy + 1);

    // Right _lines:
    if (toDraw & RightT)
        paint.drawLine(cx + 2, cy - 1, ex, cy - 1);
    if (toDraw & RightC)
        paint.drawLine(cx + 2, cy, ex, cy);
    if (toDraw & RightB)
        paint.drawLine(cx + 2, cy + 1, ex, cy + 1);

    // Intersection points.
    if (toDraw & Int11)
        paint.drawPoint(cx - 1, cy - 1);
    if (toDraw & Int12)
        paint.drawPoint(cx, cy - 1);
    if (toDraw & Int13)
        paint.drawPoint(cx + 1, cy - 1);

    if (toDraw & Int21)
        paint.drawPoint(cx - 1, cy);
    if (toDraw & Int22)
        paint.drawPoint(cx, cy);
    if (toDraw & Int23)
        paint.drawPoint(cx + 1, cy);

    if (toDraw & Int31)
        paint.drawPoint(cx - 1, cy + 1);
    if (toDraw & Int32)
        paint.drawPoint(cx, cy + 1);
    if (toDraw & Int33)
        paint.drawPoint(cx + 1, cy + 1);
}

static void drawOtherChar(QPainter &paint, int x, int y, int w, int h, uchar code) {
    // Calculate cell midpoints, end points.
    const int cx = x + w / 2;
    const int cy = y + h / 2;
    const int ex = x + w - 1;
    const int ey = y + h - 1;

    // Double dashes
    if (0x4C <= code && code <= 0x4F) {
        const int xHalfGap = qMax(w / 15, 1);
        const int yHalfGap = qMax(h / 15, 1);
        switch (code) {
        case 0x4D: // BOX DRAWINGS HEAVY DOUBLE DASH HORIZONTAL
            paint.drawLine(x, cy - 1, cx - xHalfGap - 1, cy - 1);
            paint.drawLine(x, cy + 1, cx - xHalfGap - 1, cy + 1);
            paint.drawLine(cx + xHalfGap, cy - 1, ex, cy - 1);
            paint.drawLine(cx + xHalfGap, cy + 1, ex, cy + 1);
            /* Falls through. */
        case 0x4C: // BOX DRAWINGS LIGHT DOUBLE DASH HORIZONTAL
            paint.drawLine(x, cy, cx - xHalfGap - 1, cy);
            paint.drawLine(cx + xHalfGap, cy, ex, cy);
            break;
        case 0x4F: // BOX DRAWINGS HEAVY DOUBLE DASH VERTICAL
            paint.drawLine(cx - 1, y, cx - 1, cy - yHalfGap - 1);
            paint.drawLine(cx + 1, y, cx + 1, cy - yHalfGap - 1);
            paint.drawLine(cx - 1, cy + yHalfGap, cx - 1, ey);
            paint.drawLine(cx + 1, cy + yHalfGap, cx + 1, ey);
            /* Falls through. */
        case 0x4E: // BOX DRAWINGS LIGHT DOUBLE DASH VERTICAL
            paint.drawLine(cx, y, cx, cy - yHalfGap - 1);
            paint.drawLine(cx, cy + yHalfGap, cx, ey);
            break;
        }
    }

    // Rounded corner characters
    else if (0x6D <= code && code <= 0x70) {
        const int r = w * 3 / 8;
        const int d = 2 * r;
        switch (code) {
        case 0x6D: // BOX DRAWINGS LIGHT ARC DOWN AND RIGHT
            paint.drawLine(cx, cy + r, cx, ey);
            paint.drawLine(cx + r, cy, ex, cy);
            paint.drawArc(cx, cy, d, d, 90 * 16, 90 * 16);
            break;
        case 0x6E: // BOX DRAWINGS LIGHT ARC DOWN AND LEFT
            paint.drawLine(cx, cy + r, cx, ey);
            paint.drawLine(x, cy, cx - r, cy);
            paint.drawArc(cx - d, cy, d, d, 0 * 16, 90 * 16);
            break;
        case 0x6F: // BOX DRAWINGS LIGHT ARC UP AND LEFT
            paint.drawLine(cx, y, cx, cy - r);
            paint.drawLine(x, cy, cx - r, cy);
            paint.drawArc(cx - d, cy - d, d, d, 270 * 16, 90 * 16);
            break;
        case 0x70: // BOX DRAWINGS LIGHT ARC UP AND RIGHT
            paint.drawLine(cx, y, cx, cy - r);
            paint.drawLine(cx + r, cy, ex, cy);
            paint.drawArc(cx, cy - d, d, d, 180 * 16, 90 * 16);
            break;
        }
    }

    // Diagonals
    else if (0x71 <= code && code <= 0x73) {
        switch (code) {
        case 0x71: // BOX DRAWINGS LIGHT DIAGONAL UPPER RIGHT TO LOWER LEFT
            paint.drawLine(ex, y, x, ey);
            break;
        case 0x72: // BOX DRAWINGS LIGHT DIAGONAL UPPER LEFT TO LOWER RIGHT
            paint.drawLine(x, y, ex, ey);
            break;
        case 0x73: // BOX DRAWINGS LIGHT DIAGONAL CROSS
            paint.drawLine(ex, y, x, ey);
            paint.drawLine(x, y, ex, ey);
            break;
        }
    }
}

void TerminalDisplay::drawLineCharString(QPainter &painter, int x, int y,
                                         const std::wstring &str,
                                         const Character *attributes) const {
    const QPen &currentPen = painter.pen();

#if !defined(Q_OS_WIN)
    if ((attributes->rendition & RE_BOLD) && _boldIntense) {
        QPen boldPen(currentPen);
        boldPen.setWidth(3);
        painter.setPen(boldPen);
    }
#else
    Q_UNUSED(attributes);
#endif

    for (size_t i = 0; i < str.length(); i++) {
        uint8_t code = static_cast<uint8_t>(str[i] & 0xffU);
        if (LineChars[code])
            drawLineChar(painter, static_cast<int>(x + (_fontWidth * i)), y, _fontWidth, _fontHeight,
                                     code);
        else
            drawOtherChar(painter, static_cast<int>(x + (_fontWidth * i)), y, _fontWidth, _fontHeight,
                                        code);
    }

    painter.setPen(currentPen);
}

void TerminalDisplay::drawLineCharString(QPainter &painter, int x, int y,
                                         wchar_t ch,
                                         const Character *attributes) const {
    const QPen &currentPen = painter.pen();

#if !defined(Q_OS_WIN)
    if ((attributes->rendition & RE_BOLD) && _boldIntense) {
        QPen boldPen(currentPen);
        boldPen.setWidth(3);
        painter.setPen(boldPen);
    }
#else
    Q_UNUSED(attributes);
#endif

    uint8_t code = static_cast<uint8_t>(ch & 0xffU);
    if (LineChars[code])
        drawLineChar(painter, x, y, _fontWidth, _fontHeight, code);
    else
        drawOtherChar(painter, x, y, _fontWidth, _fontHeight, code);

    painter.setPen(currentPen);
}

void TerminalDisplay::setKeyboardCursorShape(
        QTermWidget::KeyboardCursorShape shape) {
    _cursorShape = shape;

    updateCursor();
}

QTermWidget::KeyboardCursorShape TerminalDisplay::keyboardCursorShape() const {
    return _cursorShape;
}

void TerminalDisplay::setKeyboardCursorColor(bool useForegroundColor,
                                             const QColor &color) {
    if (useForegroundColor)
        _cursorColor = QColor(); // an invalid color means that
                                                         // the foreground color of the
                                                         // current character should
                                                         // be used

    else
        _cursorColor = color;
}

QColor TerminalDisplay::keyboardCursorColor() const { return _cursorColor; }

void TerminalDisplay::setOpacity(qreal opacity) {
    _opacity = qBound(static_cast<qreal>(0), opacity, static_cast<qreal>(1));
}

void TerminalDisplay::setBackgroundPixmap(QPixmap *backgroundImage) {
    _backgroundPixmapRef = backgroundImage;
    if (backgroundImage != nullptr) {
        setAttribute(Qt::WA_OpaquePaintEvent, false);
    } else {
        if (_backgroundMovie == nullptr && (!_backgroundVideoPlayer->isPlaying()) &&
                _backgroundImage.isNull())
            setAttribute(Qt::WA_OpaquePaintEvent, true);
    }
}

void TerminalDisplay::reloadBackgroundPixmap(void) { update(); }

void TerminalDisplay::setBackgroundImage(const QString &backgroundImage) {
    if (!backgroundImage.isEmpty()) {
        _backgroundImage.load(backgroundImage);
        setAttribute(Qt::WA_OpaquePaintEvent, false);
    } else {
        _backgroundImage = QPixmap();
        if (_backgroundMovie == nullptr && (!_backgroundVideoPlayer->isPlaying()) &&
                !_backgroundPixmapRef)
            setAttribute(Qt::WA_OpaquePaintEvent, true);
    }
}

void TerminalDisplay::setBackgroundMovie(const QString &backgroundImage) {
    QMovie *movie = nullptr;
    if (!backgroundImage.isEmpty()) {
        movie = new QMovie(backgroundImage);
    }
    if (movie && movie->isValid()) {
        if (_backgroundMovie != nullptr) {
            _backgroundMovie->stop();
            QObject::disconnect(_backgroundMovie, nullptr, this, nullptr);
            delete _backgroundMovie;
        }
        _backgroundMovie = movie;
        QObject::connect(_backgroundMovie, &QMovie::frameChanged, this,
                                         [&] { update(); });
        setAttribute(Qt::WA_OpaquePaintEvent, false);
        _backgroundMovie->start();
    } else {
        if (_backgroundMovie != nullptr) {
            _backgroundMovie->stop();
            QObject::disconnect(_backgroundMovie, nullptr, this, nullptr);
            delete _backgroundMovie;
        }
        _backgroundMovie = nullptr;
        if (_backgroundImage.isNull() && (!_backgroundVideoPlayer->isPlaying()) &&
                !_backgroundPixmapRef)
            setAttribute(Qt::WA_OpaquePaintEvent, true);
        if (movie)
            delete movie;
    }
}

void TerminalDisplay::setBackgroundVideo(const QString &backgroundVideo) {
    if (!backgroundVideo.isEmpty()) {
        _backgroundVideoPlayer->setSource(QUrl::fromLocalFile(backgroundVideo));
        _backgroundVideoPlayer->play();
        setAttribute(Qt::WA_OpaquePaintEvent, false);
    } else {
        _backgroundVideoPlayer->stop();
        _backgroundVideoPlayer->setSource(QUrl());
        _backgroundVideoFrame = QPixmap();
        if (_backgroundMovie == nullptr && _backgroundImage.isNull() &&
                !_backgroundPixmapRef)
            setAttribute(Qt::WA_OpaquePaintEvent, true);
    }
}

void TerminalDisplay::setBackgroundMode(BackgroundMode mode) {
    _backgroundMode = mode;
}

void TerminalDisplay::drawBackground(QPainter &painter, const QRect &rect,
                                     const QColor &backgroundColor,
                                     bool useOpacitySetting) {
    QPixmap currentBackgroundImage = _backgroundImage;
    if (_backgroundMovie != nullptr) {
        currentBackgroundImage = _backgroundMovie->currentPixmap();
    }
    if (_backgroundVideoPlayer->isPlaying()) {
        currentBackgroundImage = _backgroundVideoFrame;
    }
    // The whole widget rectangle is filled by the background color from
    // the color scheme set in setColorTable(), while the scrollbar is
    // left to the widget style for a consistent look.
    if (useOpacitySetting) {
        QColor color(backgroundColor);
        if (currentBackgroundImage.isNull()) {
            color.setAlphaF(1.0);
        } else {
            color.setAlphaF(_opacity);
        }
        painter.save();
        painter.setCompositionMode(QPainter::CompositionMode_SourceOver);
        painter.fillRect(rect, color);
        painter.restore();
    } else
        painter.fillRect(rect, backgroundColor);
}

void TerminalDisplay::drawCursor(QPainter &painter, const QRect &rect,
                                 const QColor &foregroundColor,
                                 const QColor & /*backgroundColor*/,
                                 bool &invertCharacterColor, bool preedit) {
    QRectF cursorRect = rect;
    cursorRect.setHeight(_fontHeight - _lineSpacing - 1);

    if (!_cursorBlinking) {
        if (_cursorColor.isValid())
            painter.setPen(_cursorColor);
        else
            painter.setPen(foregroundColor);

        if (_cursorShape == Emulation::KeyboardCursorShape::BlockCursor) {
            // draw the cursor outline, adjusting the area so that
            // it is draw entirely inside 'rect'
            float penWidth = qMax(1, painter.pen().width());

            if (preedit) {
                // with is single character, so the cursor width should be the same as
                // the character width
                cursorRect.setWidth(_fontWidth);
            }

            painter.drawRect(cursorRect.adjusted(penWidth / 2, penWidth / 2, -penWidth / 2, -penWidth / 2));

            if (preedit || hasFocus()) {
                painter.fillRect(cursorRect, _cursorColor.isValid() ? _cursorColor
                                                                                                                        : foregroundColor);
                if (!_cursorColor.isValid()) {
                    // invert the colour used to draw the text to ensure that the
                    // character at the cursor position is readable
                    invertCharacterColor = true;
                }
            }
        } else if (_cursorShape == Emulation::KeyboardCursorShape::UnderlineCursor)
            painter.drawLine(cursorRect.left(), cursorRect.bottom(),
                                             cursorRect.right(), cursorRect.bottom());
        else if (_cursorShape == Emulation::KeyboardCursorShape::IBeamCursor)
            painter.drawLine(cursorRect.left(), cursorRect.top(), cursorRect.left(),
                                             cursorRect.bottom());
    }
}

void TerminalDisplay::drawCharacters(QPainter &painter, const QRect &rect,
                                     const std::wstring &text,
                                     const Character *style,
                                     bool invertCharacterColor,
                                     bool tooWide) {
    // don't draw text which is currently blinking
    if (_blinking && (style->rendition & RE_BLINK))
        return;

    // don't draw concealed characters
    if (style->rendition & RE_CONCEAL)
        return;

    // setup bold and underline
    bool useBold =
            ((style->rendition & RE_BOLD) && _boldIntense) || font().bold();
    const bool useUnderline =
            style->rendition & RE_UNDERLINE || font().underline();
    const bool useItalic = style->rendition & RE_ITALIC || font().italic();
    const bool useStrikeOut =
            style->rendition & RE_STRIKEOUT || font().strikeOut();
    const bool useOverline = style->rendition & RE_OVERLINE || font().overline();

    QFont font = painter.font();
    if (font.bold() != useBold || font.underline() != useUnderline ||
            font.italic() != useItalic || font.strikeOut() != useStrikeOut ||
            font.overline() != useOverline) {
#if !defined(Q_OS_WIN)
        font.setBold(useBold);
#endif
        font.setUnderline(useUnderline);
        font.setItalic(useItalic);
        font.setStrikeOut(useStrikeOut);
        font.setOverline(useOverline);
        painter.setFont(font);
    }

    // setup pen
    const CharacterColor &textColor =
            (invertCharacterColor ? style->backgroundColor : style->foregroundColor);
    const QColor color = textColor.color(_colorTable);
    QPen pen = painter.pen();
    if (pen.color() != color) {
        pen.setColor(color);
        painter.setPen(color);
    }

    // FIXME: Here is a hack to solve the East Asian language symbol
    // "“‘"　rendering issue.
    //        But it is not a good solution. We should find a better way to solve
    //        this issue.
    int font_width = _charWidth->string_font_width(text);
    int width = CharWidth::string_unicode_width(text);
    if (_fix_quardCRT_issue33 && font_width != width) {
        int single_rect_width = rect.width() / width;
        for (size_t i = 0; i < text.length(); i++) {
            wchar_t line_char = text[i];
            if (isLineChar(line_char)) {
                drawLineCharString(painter, static_cast<int>(rect.x() + single_rect_width * i), rect.y(),
                                                     line_char, style);
            } else {
                if (_charWidth->font_width(line_char) !=
                        CharWidth::unicode_width(line_char)) {
                    // https://github.com/QQxiaoming/quardCRT/issues/33#issuecomment-2044020900
                    // | left         | center       | right        |
                    // | ------------ | ------------ | ------------ |
                    // | L'’' U+2019 | L'×' U+00D7 | L'‘' U+2018 |
                    // | L'”' U+201D | L'÷' U+00F7 | L'“' U+201C |
                    // |              | L'‖' U+2016  | L'‚' U+201A |
                    // |              |              | L'‛' U+201B |
                    const QList<uint16_t> right_chars = {0x201C, 0x2018, 0x201A, 0x201B};
                    const QList<uint16_t> center_chars = {0x00D7, 0x00F7, 0x2016};
                    const QList<uint16_t> left_chars = {0x201D, 0x2019, 0x2580, 0x2584, 0x2588};
                    if (right_chars.contains(line_char)) {
                        int offset =
                                single_rect_width * (_charWidth->font_width(line_char) -
                                                                         CharWidth::unicode_width(line_char));
                        painter.save();
                        QRect rightHalfRect(static_cast<int>(rect.x() + single_rect_width * i), rect.y(),
                                                                single_rect_width, _fontHeight);
                        painter.setClipRect(rightHalfRect);
                        painter.drawText(static_cast<int>(rect.x() + single_rect_width * i - offset),
                                                         rect.y() + _fontAscent + _lineSpacing,
                                                         QString::fromWCharArray(&line_char, 1));
                        painter.restore();
                    } else if (center_chars.contains(line_char)) {
                        int offset = single_rect_width *
                                                 (_charWidth->font_width(line_char) -
                                                    CharWidth::unicode_width(line_char)) /
                                                 2;
                        painter.save();
                        QRect rightHalfRect(static_cast<int>(rect.x() + single_rect_width * i), rect.y(),
                                                                single_rect_width, _fontHeight);
                        painter.setClipRect(rightHalfRect);
                        painter.drawText(static_cast<int>(rect.x() + single_rect_width * i - offset),
                                                         rect.y() + _fontAscent + _lineSpacing,
                                                         QString::fromWCharArray(&line_char, 1));
                        painter.restore();
                    } else if (left_chars.contains(line_char)) {
                        QRect rectangle(static_cast<int>(rect.x() + single_rect_width * i), rect.y(),
                                                        single_rect_width, _fontHeight);
                        painter.drawText(rectangle, 0,
                                                         QString::fromWCharArray(&line_char, 1));
                    } else {
                        painter.drawText(static_cast<int>(rect.x() + single_rect_width * i),
                                                         rect.y() + _fontAscent + _lineSpacing,
                                                         QString::fromWCharArray(&line_char, 1));
                    }
                } else {
                    painter.drawText(static_cast<int>(rect.x() + single_rect_width * i),
                                                     rect.y() + _fontAscent + _lineSpacing,
                                                     QString::fromWCharArray(&line_char, 1));
                }
            }
        }
    } else {
        // draw text
        if (isLineCharString(text)) {
            drawLineCharString(painter, rect.x(), rect.y(), text, style);
        } else {
            // Force using LTR as the document layout for the terminal area, because
            // there is no use cases for RTL emulator and RTL terminal application.
            //
            // This still allows RTL characters to be rendered in the RTL way.
            painter.setLayoutDirection(Qt::LeftToRight);

            if (_bidiEnabled) {
                if (tooWide) {
                    QRect drawRect(rect.topLeft(), rect.size());
                    drawRect.setHeight(rect.height() + _drawTextAdditionHeight);
                    painter.drawText(drawRect, Qt::AlignBottom, QString::fromStdWString(text));
                } else {
                    painter.drawText(rect.x(), rect.y() + _fontAscent + _lineSpacing,
                                    QString::fromStdWString(text));
                }
            } else {
                QRect drawRect(rect.topLeft(), rect.size());
                drawRect.setHeight(rect.height() + _drawTextAdditionHeight);
                painter.drawText(drawRect, Qt::AlignBottom, LTR_OVERRIDE_CHAR + QString::fromStdWString(text));
            }
        }
    }
}

void TerminalDisplay::drawTextFragment(QPainter &painter, const QRect &rect,
                                       const std::wstring &text,
                                       Character* style,
                                       bool tooWide,
                                       bool isSelection) {
    painter.save();

    // when the selected text is not opaque, the text is drawn with inverted
    // colors but else the text is drawn with the normal colors
    if (_selectedTextOpacity < 1.0) {
        if (isSelection) {
            CharacterColor f = style->foregroundColor;
            CharacterColor b = style->backgroundColor;
            style->foregroundColor = b;
            style->backgroundColor = f;
        }
    }

    // setup painter
    const QColor foregroundColor = style->foregroundColor.color(_colorTable);
    const QColor backgroundColor = style->backgroundColor.color(_colorTable);

    // draw background if different from the display's background color
    if (backgroundColor != _colorTable[DEFAULT_BACK_COLOR].color) {
        drawBackground(painter, rect, backgroundColor,
                                     false /* do not use transparency */);
    }

    // draw cursor shape if the current character is the cursor
    // this may alter the foreground and background colors
    bool invertCharacterColor = false;
    if (style->rendition & RE_CURSOR)
        drawCursor(painter, rect, foregroundColor, backgroundColor,
                             invertCharacterColor);

    // draw text
    drawCharacters(painter, rect, text, style, invertCharacterColor, tooWide);

    painter.restore();

    if (_selectedTextOpacity < 1.0) {
        if (isSelection) {
            painter.save();
            painter.setOpacity(_selectedTextOpacity);
            painter.setRenderHint(QPainter::SmoothPixmapTransform, false);
            painter.setRenderHint(QPainter::Antialiasing, false);
            painter.fillRect(rect, CharacterColor(COLOR_SPACE_DEFAULT, DEFAULT_FORE_COLOR)
                                                     .color(_colorTable));
            painter.restore();
            CharacterColor f = style->foregroundColor;
            CharacterColor b = style->backgroundColor;
            style->foregroundColor = b;
            style->backgroundColor = f;
        }
    }
}

#if 0
/*!
        Set XIM Position
*/
void TerminalDisplay::setCursorPos(const int curx, const int cury) {
    QPoint tL  = contentsRect().topLeft();
    int    tLx = tL.x();
    int    tLy = tL.y();

    int xpos, ypos;
    ypos = _topMargin + tLy + _fontHeight*(cury-1) + _fontAscent;
    xpos = _leftMargin + tLx + _fontWidth*curx;
    //setMicroFocusHint(xpos, ypos, 0, _fontHeight); //### ???
    // fprintf(stderr, "x/y = %d/%d\txpos/ypos = %d/%d\n", curx, cury, xpos, ypos);
    _cursorLine = cury;
    _cursorCol = curx;
}
#endif

// scrolls the image by 'lines', down if lines > 0 or up otherwise.
//
// the terminal emulation keeps track of the scrolling of the character
// image as it receives input, and when the view is updated, it calls
// scrollImage() with the final scroll amount.  this improves performance
// because scrolling the display is much cheaper than re-rendering all the text
// for the part of the image which has moved up or down. Instead only new lines
// have to be drawn
void TerminalDisplay::scrollImage(int lines, const QRect &screenWindowRegion) {
    // if the flow control warning is enabled this will interfere with the
    // scrolling optimizations and cause artifacts.  the simple solution here
    // is to just disable the optimization whilst it is visible
    if (_outputSuspendedLabel && _outputSuspendedLabel->isVisible())
        return;

    // constrain the region to the display
    // the bottom of the region is capped to the number of lines in the display's
    // internal image - 2, so that the height of 'region' is strictly less
    // than the height of the internal image.
    QRect region = screenWindowRegion;
    region.setBottom(qMin(region.bottom(), this->_lines - 2));

    // return if there is nothing to do
    if (lines == 0 || _image == nullptr || !region.isValid() ||
            (region.top() + abs(lines)) >= region.bottom() ||
            this->_lines <= region.height())
        return;

    // hide terminal size label to prevent it being scrolled
    if (_resizeWidget && _resizeWidget->isVisible())
        _resizeWidget->hide();

    // Note:  With Qt 4.4 the left edge of the scrolled area must be at 0
    // to get the correct (newly exposed) part of the widget repainted.
    //
    // The right edge must be before the left edge of the scroll bar to
    // avoid triggering a repaint of the entire widget, the distance is
    // given by SCROLLBAR_CONTENT_GAP
    //
    // Set the QT_FLUSH_PAINT environment variable to '1' before starting the
    // application to monitor repainting.
    //
    int scrollBarWidth =
            _scrollBar->isHidden() ? 0
            : _scrollBar->style()->styleHint(QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar)
                    ? 0
                    : _scrollBar->width();
    const int SCROLLBAR_CONTENT_GAP = scrollBarWidth == 0 ? 0 : 1;
    QRect scrollRect;
    if (_scrollbarLocation == QTermWidget::ScrollBarLeft) {
        scrollRect.setLeft(scrollBarWidth + SCROLLBAR_CONTENT_GAP);
        scrollRect.setRight(width());
    } else {
        scrollRect.setLeft(0);
        scrollRect.setRight(width() - scrollBarWidth - SCROLLBAR_CONTENT_GAP);
    }
    void *firstCharPos = &_image[region.top() * this->_columns];
    void *lastCharPos = &_image[(region.top() + abs(lines)) * this->_columns];

    int top = _topMargin + (region.top() * _fontHeight);
    int linesToMove = region.height() - abs(lines);
    int bytesToMove = linesToMove * this->_columns * sizeof(Character);

    Q_ASSERT(linesToMove > 0);
    Q_ASSERT(bytesToMove > 0);

    // scroll internal image
    if (lines > 0) {
        // check that the memory areas that we are going to move are valid
        Q_ASSERT((char *)lastCharPos + bytesToMove <
                         (char *)(_image + (this->_lines * this->_columns)));

        Q_ASSERT((lines * this->_columns) < _imageSize);

        // scroll internal image down
        memmove(firstCharPos, lastCharPos, bytesToMove);

        // set region of display to scroll
        scrollRect.setTop(top);
    } else {
        // check that the memory areas that we are going to move are valid
        Q_ASSERT((char *)firstCharPos + bytesToMove <
                         (char *)(_image + (this->_lines * this->_columns)));

        // scroll internal image up
        memmove(lastCharPos, firstCharPos, bytesToMove);

        // set region of the display to scroll
        scrollRect.setTop(top + abs(lines) * _fontHeight);
    }
    scrollRect.setHeight(linesToMove * _fontHeight);

    Q_ASSERT(scrollRect.isValid() && !scrollRect.isEmpty());

    // scroll the display vertically to match internal _image
    scroll(0, _fontHeight * (-lines), scrollRect);
}

QRegion TerminalDisplay::hotSpotRegion() const {
    QRegion region;
    const auto hotSpots = _filterChain->hotSpots();
    for (Filter::HotSpot *const hotSpot : hotSpots) {
        QRect r;
        if (hotSpot->startLine() == hotSpot->endLine()) {
            r.setLeft(hotSpot->startColumn());
            r.setTop(hotSpot->startLine());
            r.setRight(hotSpot->endColumn());
            r.setBottom(hotSpot->endLine());
            region |= imageToWidget(r);
            ;
        } else {
            r.setLeft(hotSpot->startColumn());
            r.setTop(hotSpot->startLine());
            r.setRight(_columns);
            r.setBottom(hotSpot->startLine());
            region |= imageToWidget(r);
            ;
            for (int line = hotSpot->startLine() + 1; line < hotSpot->endLine();
                     line++) {
                r.setLeft(0);
                r.setTop(line);
                r.setRight(_columns);
                r.setBottom(line);
                region |= imageToWidget(r);
                ;
            }
            r.setLeft(0);
            r.setTop(hotSpot->endLine());
            r.setRight(hotSpot->endColumn());
            r.setBottom(hotSpot->endLine());
            region |= imageToWidget(r);
            ;
        }
    }
    return region;
}

void TerminalDisplay::processFilters() {
    if (!_screenWindow)
        return;

    QRegion preUpdateHotSpots = hotSpotRegion();

    // use _screenWindow->getImage() here rather than _image because
    // other classes may call processFilters() when this display's
    // ScreenWindow emits a scrolled() signal - which will happen before
    // updateImage() is called on the display and therefore _image is
    // out of date at this point
    _filterChain->setImage(
            _screenWindow->getImage(), _screenWindow->windowLines(),
            _screenWindow->windowColumns(), _screenWindow->getLineProperties());
    _filterChain->process();

    QRegion postUpdateHotSpots = hotSpotRegion();

    update(preUpdateHotSpots | postUpdateHotSpots);
}

void TerminalDisplay::updateImage() {
    if (!_screenWindow)
        return;

    // optimization - scroll the existing image where possible and
    // avoid expensive text drawing for parts of the image that
    // can simply be moved up or down
    scrollImage(_screenWindow->scrollCount(), _screenWindow->scrollRegion());
    _screenWindow->resetScrollCount();

    if (!_image) {
        // Create _image.
        // The emitted changedContentSizeSignal also leads to getImage being
        // recreated, so do this first.
        updateImageSize();
    }

    Character *const newimg = _screenWindow->getImage();
    int lines = _screenWindow->windowLines();
    int columns = _screenWindow->windowColumns();

    setScroll(_screenWindow->currentLine(), _screenWindow->lineCount());

    Q_ASSERT(this->_usedLines <= this->_lines);
    Q_ASSERT(this->_usedColumns <= this->_columns);

    int y, x, len;

    QPoint tL = contentsRect().topLeft();
    int tLx = tL.x();
    int tLy = tL.y();
    _hasBlinker = false;

    CharacterColor cf;         // undefined
    CharacterColor _clipboard; // undefined
    int cr = -1;               // undefined

    const int linesToUpdate = qMin(this->_lines, qMax(0, lines));
    const int columnsToUpdate = qMin(this->_columns, qMax(0, columns));

    wchar_t *disstrU = new wchar_t[columnsToUpdate];
    char *dirtyMask = new char[columnsToUpdate + 2];
    QRegion dirtyRegion;

    // debugging variable, this records the number of lines that are found to
    // be 'dirty' ( ie. have changed from the old _image to the new _image ) and
    // which therefore need to be repainted
    for (y = 0; y < linesToUpdate; ++y) {
        const Character *currentLine = &_image[y * this->_columns];
        const Character *const newLine = &newimg[y * columns];

        bool updateLine = false;

        // The dirty mask indicates which characters need repainting. We also
        // mark surrounding neighbours dirty, in case the character exceeds
        // its cell boundaries
        memset(dirtyMask, 0, columnsToUpdate + 2);

        for (x = 0; x < columnsToUpdate; ++x) {
            if (newLine[x] != currentLine[x]) {
                dirtyMask[x] = true;
            }
        }

        QFontMetrics fm(font());
        if (!_resizing) // not while _resizing, we're expecting a paintEvent
            for (x = 0; x < columnsToUpdate; ++x) {
                if ((newLine[x].rendition & RE_BLINK) != 0) {
                    _hasBlinker = true;
                }

                // Start drawing if this character or the next one differs.
                // We also take the next one into account to handle the situation
                // where characters exceed their cell width.
                if (dirtyMask[x]) {
                    wchar_t c = newLine[x + 0].character;
                    if (!c)
                        continue;
                    int p = 0;
                    disstrU[p++] = c; // fontMap(c);
                    bool lineDraw = isLineChar(newLine[x+0]);
                    bool doubleWidth = (x + 1 == columnsToUpdate)
                                                                 ? false
                                                                 : (newLine[x + 1].character == 0);
                    int charWidth = fm.horizontalAdvance(QString::fromWCharArray(&c, 1));
                    bool bigWidth = _fixedFont && !doubleWidth && charWidth > _fontWidth;
                    bool smallWidth = _fixedFont && charWidth < _fontWidth;
                    cr = newLine[x].rendition;
                    _clipboard = newLine[x].backgroundColor;
                    if (newLine[x].foregroundColor != cf)
                        cf = newLine[x].foregroundColor;
                    int lln = columnsToUpdate - x;
                    for (len = 1; len < lln; ++len) {
                        const Character &ch = newLine[x + len];

                        if (!ch.character)
                            continue; // Skip trailing part of multi-col chars.

                        bool nextIsDoubleWidth =
                                (x + len + 1 == columnsToUpdate)
                                        ? false
                                        : (newLine[x + len + 1].character == 0);

                        int nxtCharWidth = fm.horizontalAdvance(QString::fromWCharArray(&newLine[x+len].character, 1));
                        bool nextIsbigWidth = _fixedFont && !nextIsDoubleWidth && nxtCharWidth > _fontWidth;
                        bool nextIsSmallWidth = _fixedFont && newLine[x+len].character && nxtCharWidth < _fontWidth;

                        if (ch.foregroundColor != cf ||
                            ch.backgroundColor != _clipboard ||
                            ch.rendition != cr ||
                            !dirtyMask[x+len] ||
                            isLineChar(ch) != lineDraw ||
                            nextIsDoubleWidth != doubleWidth ||
                            bigWidth || nextIsbigWidth ||
                            smallWidth || nextIsSmallWidth) {
                            break;
                        }

                        disstrU[p++] = c; // fontMap(c);
                    }

                    std::wstring unistr(disstrU, p);

                    bool saveFixedFont = _fixedFont;
                    if (lineDraw)
                        _fixedFont = false;
                    if (doubleWidth)
                        _fixedFont = false;

                    updateLine = true;

                    _fixedFont = saveFixedFont;
                    x += len - 1;
                }
            }

        // both the top and bottom halves of double height _lines must always be
        // redrawn although both top and bottom halves contain the same characters,
        // only the top one is actually drawn.
        if (_lineProperties.count() > y) {
            if ((_lineProperties[y] & LINE_DOUBLEHEIGHT) != 0) {
                updateLine = true;
            }
        }

        // if the characters on the line are different in the old and the new _image
        // then this line must be repainted.
        if (updateLine) {
            // add the area occupied by this line to the region which needs to be
            // repainted
            QRect dirtyRect =
                    QRect(_leftMargin + tLx, _topMargin + tLy + _fontHeight * y,
                                _fontWidth * columnsToUpdate, _fontHeight);

            dirtyRegion |= dirtyRect;
        }

        // replace the line of characters in the old _image with the
        // current line of the new _image
        memcpy((void *)currentLine, (const void *)newLine,
                     columnsToUpdate * sizeof(Character));
    }

    // if the new _image is smaller than the previous _image, then ensure that the
    // area outside the new _image is cleared
    if (linesToUpdate < _usedLines) {
        dirtyRegion |=
                QRect(_leftMargin + tLx, _topMargin + tLy + _fontHeight * linesToUpdate,
                            _fontWidth * this->_columns,
                            _fontHeight * (_usedLines - linesToUpdate));
    }
    _usedLines = linesToUpdate;

    if (columnsToUpdate < _usedColumns) {
        dirtyRegion |=
                QRect(_leftMargin + tLx + columnsToUpdate * _fontWidth,
                            _topMargin + tLy, _fontWidth * (_usedColumns - columnsToUpdate),
                            _fontHeight * this->_lines);
    }
    _usedColumns = columnsToUpdate;

    dirtyRegion |= _inputMethodData.previousPreeditRect;

    // update the parts of the display which have changed
    update(dirtyRegion);

    if (_hasBlinker && !_blinkTimer->isActive())
        _blinkTimer->start(TEXT_BLINK_DELAY);
    if (!_hasBlinker && _blinkTimer->isActive()) {
        _blinkTimer->stop();
        _blinking = false;
    }
    delete[] dirtyMask;
    delete[] disstrU;
}

void TerminalDisplay::showResizeNotification() {
    if (_terminalSizeHint && isVisible()) {
        if (_terminalSizeStartup) {
            _terminalSizeStartup = false;
            return;
        }
        if (!_resizeWidget) {
            const QString label = tr("Size: XXX x XXX");
            _resizeWidget = new QLabel(label, this);
            _resizeWidget->setMinimumWidth(
                    _resizeWidget->fontMetrics().horizontalAdvance(label));
            _resizeWidget->setMinimumHeight(_resizeWidget->sizeHint().height());
            _resizeWidget->setAlignment(Qt::AlignCenter);

            _resizeWidget->setStyleSheet(QLatin1String(
                    "background-color:palette(window);border-style:solid;border-width:"
                    "1px;border-color:palette(dark);color:palette(windowText);"));

            _resizeTimer = new QTimer(this);
            _resizeTimer->setSingleShot(true);
            connect(_resizeTimer, &QTimer::timeout, _resizeWidget, &QLabel::hide);
        }
        _resizeWidget->setText(tr("Size: %1 x %2").arg(_columns).arg(_lines));
        _resizeWidget->move((width() - _resizeWidget->width()) / 2,
                                                (height() - _resizeWidget->height()) / 2 + 20);
        _resizeWidget->show();
        _resizeTimer->start(1000);
    }
}

void TerminalDisplay::setBlinkingCursor(bool blink) {
    _hasBlinkingCursor = blink;

    if (blink && !_blinkCursorTimer->isActive() && hasFocus()) {
        // QApplication::cursorFlashTime() may be negative, and a too fast
        // blinking is not good. Also, see TerminalDisplay::keyPressEvent.
        _blinkCursorTimer->start(std::max(QApplication::cursorFlashTime(), 1000) / 2);
    }

    if (!blink && _blinkCursorTimer->isActive()) {
        _blinkCursorTimer->stop();
        if (_cursorBlinking)
            blinkCursorEvent();
        else
            _cursorBlinking = false;
    }
}

void TerminalDisplay::setBlinkingTextEnabled(bool blink) {
    _allowBlinkingText = blink;

    if (blink && !_blinkTimer->isActive() && hasFocus())
        _blinkTimer->start(TEXT_BLINK_DELAY);

    if (!blink && _blinkTimer->isActive()) {
        _blinkTimer->stop();
        _blinking = false;
    }
}

void TerminalDisplay::focusOutEvent(QFocusEvent *) {
    // trigger a repaint of the cursor so that it is both visible (in case
    // it was hidden during blinking)
    // and drawn in a focused out state
    _cursorBlinking = false;
    updateCursor();
    _blinkCursorTimer->stop();

    if (_blinking)
        blinkEvent();

    _blinkTimer->stop();

    // This signal should be emitted only in the end
    // because the focus may change in response to it.
    emit termLostFocus();
}
void TerminalDisplay::focusInEvent(QFocusEvent *) {
    if (_hasBlinkingCursor) {
        // see TerminalDisplay::setBlinkingCursor
        _blinkCursorTimer->start(std::max(QApplication::cursorFlashTime(), 1000) / 2);
    }
    updateCursor();

    if (_hasBlinker)
        _blinkTimer->start(TEXT_BLINK_DELAY);

    // This signal should be emitted only in the end
    // because the focus may change in response to it.
    emit termGetFocus();
}

void TerminalDisplay::enterEvent(QEnterEvent* event)
{
  if (gs_deadSpot.x() < 0 && _hideMouseTimer
      // NOTE: scrollBar->underMouse() doesn't work here
      && !_scrollBar->rect().contains(_scrollBar->mapFromParent(event->position().toPoint())))
  {
    gs_futureDeadSpot = event->position().toPoint();
    _hideMouseTimer->start(_mouseAutohideDelay);
  }
  QWidget::enterEvent(event);
}

void TerminalDisplay::leaveEvent(QEvent* event)
{
  if (gs_deadSpot.x() > -1)
  {
    gs_deadSpot = QPoint(-1,-1);
    QApplication::restoreOverrideCursor();
  }
  QWidget::leaveEvent(event);
}

void TerminalDisplay::paintEvent(QPaintEvent *pe) {
    QPainter paint(this);
    QRect cr = contentsRect();

    QPixmap currentBackgroundImage = _backgroundImage;
    if (_backgroundMovie != nullptr) {
        currentBackgroundImage = _backgroundMovie->currentPixmap();
    }
    if (_backgroundVideoPlayer->isPlaying()) {
        currentBackgroundImage = _backgroundVideoFrame;
    }

    if (!currentBackgroundImage.isNull()) {
        QColor background = _colorTable[DEFAULT_BACK_COLOR].color;
        if (_opacity < static_cast<qreal>(1)) {
            background.setAlphaF(_opacity);
            paint.save();
            paint.setCompositionMode(QPainter::CompositionMode_Source);
            paint.fillRect(cr, background);
            paint.restore();
        } else {
            paint.fillRect(cr, background);
        }

        paint.save();
        paint.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);

        if (_backgroundMode == Stretch) { // scale the image without keeping its
                                                                            // proportions to fill the screen
            paint.drawPixmap(cr, currentBackgroundImage, currentBackgroundImage.rect());
        } else if (_backgroundMode == Zoom) { // zoom in/out the image to fit it
            QRect r = currentBackgroundImage.rect();
            qreal wRatio = static_cast<qreal>(cr.width()) / r.width();
            qreal hRatio = static_cast<qreal>(cr.height()) / r.height();
            if (wRatio > hRatio) {
                r.setWidth(qRound(r.width() * hRatio));
                r.setHeight(cr.height());
            } else {
                r.setHeight(qRound(r.height() * wRatio));
                r.setWidth(cr.width());
            }
            r.moveCenter(cr.center());
            paint.drawPixmap(r, currentBackgroundImage,
                                             currentBackgroundImage.rect());
        } else if (_backgroundMode == Fit) { // if the image is bigger than the
                                             // terminal, zoom it out to fit it
            QRect r = currentBackgroundImage.rect();
            qreal wRatio = static_cast<qreal>(cr.width()) / r.width();
            qreal hRatio = static_cast<qreal>(cr.height()) / r.height();
            if (r.width() > cr.width()) {
                if (wRatio <= hRatio) {
                    r.setHeight(qRound(r.height() * wRatio));
                    r.setWidth(cr.width());
                } else {
                    r.setWidth(qRound(r.width() * hRatio));
                    r.setHeight(cr.height());
                }
            } else if (r.height() > cr.height()) {
                r.setWidth(qRound(r.width() * hRatio));
                r.setHeight(cr.height());
            }
            r.moveCenter(cr.center());
            paint.drawPixmap(r, currentBackgroundImage, currentBackgroundImage.rect());
        } else if (_backgroundMode ==
                             Center) { // center the image without scaling/zooming
            QRect r = currentBackgroundImage.rect();
            r.moveCenter(cr.center());
            paint.drawPixmap(r.topLeft(), currentBackgroundImage);
        } else if (_backgroundMode == Tile) { // tile the image
            QPixmap scaled = currentBackgroundImage;
            qreal wRatio =
                    static_cast<qreal>(cr.width()) / currentBackgroundImage.width();
            qreal hRatio =
                    static_cast<qreal>(cr.height()) / currentBackgroundImage.height();
            if (wRatio < 1.0 || hRatio < 1.0) {
                if (wRatio > hRatio) {
                    scaled = currentBackgroundImage.scaled(
                            currentBackgroundImage.width() * hRatio,
                            currentBackgroundImage.height() * hRatio);
                } else {
                    scaled = currentBackgroundImage.scaled(
                            currentBackgroundImage.width() * wRatio,
                            currentBackgroundImage.height() * wRatio);
                }
            }
            int x = 0;
            int y = 0;
            while (y < cr.height()) {
                while (x < cr.width()) {
                    paint.drawPixmap(x, y, scaled);
                    x += scaled.width();
                }
                x = 0;
                y += scaled.height();
            }
        } else // if (_backgroundMode == None)
        {
            paint.drawPixmap(0, 0, currentBackgroundImage);
        }

        paint.restore();
    }

    if (_drawTextTestFlag) {
        calDrawTextAdditionHeight(paint);
    }

    const QRegion regToDraw = pe->region() & cr;
    for (auto rect = regToDraw.begin(); rect != regToDraw.end(); rect++) {
        drawBackground(paint, *rect, _colorTable[DEFAULT_BACK_COLOR].color,
                                     true /* use opacity setting */);
        drawContents(paint, *rect);
    }
    drawInputMethodPreeditString(paint, preeditRect());

    if (_isLocked) {
        paint.save();
        paint.setOpacity(0.3);
        paint.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
        paint.drawPixmap(cr, _lockbackgroundImage, _lockbackgroundImage.rect());
        paint.restore();
    }

    paintFilters(paint);
}

QPoint TerminalDisplay::cursorPosition() const {
    if (_screenWindow)
        return _screenWindow->cursorPosition();
    else
        return {0, 0};
}

QRect TerminalDisplay::preeditRect() const {
    const int preeditLength =
            CharWidth::string_unicode_width(_inputMethodData.preeditString);

    if (preeditLength == 0)
        return {};

    return QRect(_leftMargin + _fontWidth * cursorPosition().x(),
                             _topMargin + _fontHeight * cursorPosition().y(),
                             _fontWidth * preeditLength, _fontHeight);
}

void TerminalDisplay::drawInputMethodPreeditString(QPainter &painter, const QRect &rect) {
    if (_inputMethodData.preeditString.empty())
        return;

    bool invertColors = false;
    QColor background = _colorTable[DEFAULT_BACK_COLOR].color;
    QColor foreground = _colorTable[DEFAULT_FORE_COLOR].color;
    Character style;
    style.character = ' ';
    style.foregroundColor =
            CharacterColor(COLOR_SPACE_RGB, _colorTable[_preeditColorIndex].color);
    style.backgroundColor =
            CharacterColor(COLOR_SPACE_RGB, _colorTable[DEFAULT_BACK_COLOR].color);
    style.rendition = DEFAULT_RENDITION;
    drawBackground(painter, rect, background, true);
    drawCursor(painter, rect, foreground, background, invertColors, true);
    invertColors = false;
    drawCharacters(painter, rect, _inputMethodData.preeditString, &style,
                                 invertColors);

    _inputMethodData.previousPreeditRect = rect;
}

FilterChain *TerminalDisplay::filterChain() const { return _filterChain; }

void TerminalDisplay::paintFilters(QPainter &painter) {
    // get color of character under mouse and use it to draw
    // lines for filters
    QPoint cursorPos = mapFromGlobal(QCursor::pos());
    int cursorLine;
    int cursorColumn;
    int leftMargin = _leftBaseMargin +
                    ((_scrollbarLocation == QTermWidget::ScrollBarLeft &&
                        !_scrollBar->style()->styleHint(
                            QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
                            ? _scrollBar->width()
                            : 0);

    getCharacterPosition(cursorPos, cursorLine, cursorColumn);
    Character cursorCharacter = _image[loc(cursorColumn, cursorLine)];

    painter.setPen(QPen(cursorCharacter.foregroundColor.color(colorTable())));

    // iterate over hotspots identified by the display's currently active filters
    // and draw appropriate visuals to indicate the presence of the hotspot

    QList<Filter::HotSpot *> spots = _filterChain->hotSpots();
    QListIterator<Filter::HotSpot *> iter(spots);
    while (iter.hasNext()) {
        Filter::HotSpot *spot = iter.next();

        QRegion region;
        if (spot->type() == Filter::HotSpot::Link) {
            QRect r;
            if (spot->startLine() == spot->endLine()) {
                r.setCoords(spot->startColumn() * _fontWidth + 1 + leftMargin,
                                spot->startLine() * _fontHeight + 1 + _topBaseMargin,
                                spot->endColumn() * _fontWidth - 1 + leftMargin,
                                (spot->endLine() + 1) * _fontHeight - 1 + _topBaseMargin);
                region |= r;
            } else {
                r.setCoords(spot->startColumn() * _fontWidth + 1 + leftMargin,
                                spot->startLine() * _fontHeight + 1 + _topBaseMargin,
                                _columns * _fontWidth - 1 + leftMargin,
                                (spot->startLine() + 1) * _fontHeight - 1 + _topBaseMargin);
                region |= r;
                for (int line = spot->startLine() + 1; line < spot->endLine(); line++) {
                    r.setCoords(0 * _fontWidth + 1 + leftMargin,
                                    line * _fontHeight + 1 + _topBaseMargin,
                                    _columns * _fontWidth - 1 + leftMargin,
                                    (line + 1) * _fontHeight - 1 + _topBaseMargin);
                    region |= r;
                }
                r.setCoords(0 * _fontWidth + 1 + leftMargin,
                                spot->endLine() * _fontHeight + 1 + _topBaseMargin,
                                spot->endColumn() * _fontWidth - 1 + leftMargin,
                                (spot->endLine() + 1) * _fontHeight - 1 + _topBaseMargin);
                region |= r;
            }
        }

        for (int line = spot->startLine(); line <= spot->endLine(); line++) {
            int startColumn = 0;
            int endColumn = _columns - 1; // TODO use number of _columns which are
                                          // actually occupied on this line rather
                                          // than the width of the display in _columns

            // ignore whitespace at the end of the lines
            do {
                if (endColumn <= 0)
                    break;
                uint64_t ucode = _image[loc(startColumn, line)].character;
                if (ucode > 0xffff)
                    break;
                if (QChar(_image[loc(startColumn, line)].character).isSpace())
                    break;
                endColumn--;
            } while (true);

            // increment here because the column which we want to set 'endColumn' to
            // is the first whitespace character at the end of the line
            endColumn++;

            if (line == spot->startLine())
                startColumn = spot->startColumn();
            if (line == spot->endLine())
                endColumn = spot->endColumn();

            // subtract one pixel from
            // the right and bottom so that
            // we do not overdraw adjacent
            // hotspots
            //
            // subtracting one pixel from all sides also prevents an edge case where
            // moving the mouse outside a link could still leave it underlined
            // because the check below for the position of the cursor
            // finds it on the border of the target area
            QRect r;
            r.setCoords(startColumn * _fontWidth + 1 + leftMargin,
                                    line * _fontHeight + 1 + _topBaseMargin,
                                    endColumn * _fontWidth - 1 + leftMargin,
                                    (line + 1) * _fontHeight - 1 + _topBaseMargin);
            // Underline link hotspots
            if (spot->type() == Filter::HotSpot::Link) {
                QFontMetrics metrics(font());

                // find the baseline (which is the invisible line that the characters in
                // the font sit on, with some having tails dangling below)
                int baseline = r.bottom() - metrics.descent();
                // find the position of the underline below that
                int underlinePos = baseline + metrics.underlinePos();
                if (region.contains(mapFromGlobal(QCursor::pos()))) {
                    painter.drawLine(r.left(), underlinePos, r.right(), underlinePos);
                }
            }
            // Marker hotspots simply have a transparent rectanglular shape
            // drawn on top of them
            else if (spot->type() == Filter::HotSpot::Marker) {
                QColor markerColor = spot->color();
                markerColor.setAlpha(120);
                painter.fillRect(r, markerColor);
            }
        }
    }
}

// NOTE: This should be called only when "_fixedFont" is set to "false" (temporarily).
int TerminalDisplay::textWidth(const int startColumn, const int length, const int line) const {
    QFontMetrics fm(font());
    int result = 0;
    for (int column = 0; column < length; column++) {
        auto c = _image[loc(startColumn + column, line)];
        // Take care of double-column characters and those with small widths.
        // Exclude line characters, as some of them are ambiguous ('A') [1]
        // [1] http://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt
        if (_fixedFont_original && !isLineChar(c)) { 
            // c == 0 may happen here after a double-column character
            result += fm.horizontalAdvance(QLatin1Char(REPCHAR[0]));
        } else {
            result += fm.horizontalAdvance(QChar(static_cast<uint>(c.character)));
        }
    }
    return result;
}

QRect TerminalDisplay::calculateTextArea(int topLeftX, int topLeftY,
                                            int startColumn, int line,
                                            int length) {
    int left =
            _fixedFont ? _fontWidth * startColumn : textWidth(0, startColumn, line);
    int top = _fontHeight * line;
    int width =
            _fixedFont ? _fontWidth * length : textWidth(startColumn, length, line);
    return {_leftMargin + topLeftX + left, _topMargin + topLeftY + top, width,
                    _fontHeight};
}

void TerminalDisplay::drawContents(QPainter &paint, const QRect &rect) {
    QPoint tL = contentsRect().topLeft();
    int tLx = tL.x();
    int tLy = tL.y();

    int lux = qMin(_usedColumns - 1, qMax(0, (rect.left() - tLx - _leftMargin) / _fontWidth));
    int luy = qMin(_usedLines - 1, qMax(0, (rect.top() - tLy - _topMargin) / _fontHeight));
    int rlx = qMin(_usedColumns - 1, qMax(0, (rect.right() - tLx - _leftMargin) / _fontWidth));
    int rly = qMin(_usedLines - 1, qMax(0, (rect.bottom() - tLy - _topMargin) / _fontHeight));

    QFontMetrics fm(font());
    const int numberOfColumns = _usedColumns;
    std::wstring unistr;
    unistr.reserve(numberOfColumns);
    for (int y = luy; y <= rly; y++) {
        quint32 c = _image[loc(lux, y)].character;
        int x = lux;
        if (!c && x)
            x--; // Search for start of multi-column character
        for (; x <= rlx; x++) {
            int len = 1;
            int p = 0;

            // reset our buffer to the number of columns
            int bufferSize = numberOfColumns;
            unistr.resize(bufferSize);

            // is this a single character or a sequence of characters ?
            if (_image[loc(x, y)].rendition & RE_EXTENDED_CHAR) {
                // sequence of characters
                ushort extendedCharLength = 0;
                uint* chars = ExtendedCharTable::instance
                                .lookupExtendedChar(_image[loc(x,y)].character,extendedCharLength);
                if (chars) {
                    Q_ASSERT(extendedCharLength > 1);
                    bufferSize += extendedCharLength - 1;
                    unistr.resize(bufferSize);
                    for ( int index = 0 ; index < extendedCharLength ; index++ ) {
                        Q_ASSERT( p < bufferSize );
                        unistr[p++] = chars[index];
                    }
                }
            } else {
                // single character
                c = _image[loc(x, y)].character;
                if (c) {
                    Q_ASSERT(p < bufferSize);
                    unistr[p++] = c; // fontMap(c);
                }
            }

            bool lineDraw = isLineChar(_image[loc(x,y)]);
            bool doubleWidth =
                    (_image[qMin(loc(x, y) + 1, _imageSize)].character == 0);
            int charWidth = fm.horizontalAdvance(QString::fromWCharArray((wchar_t *)&c, 1));
            bool bigWidth = _fixedFont && !doubleWidth && charWidth > _fontWidth;
            bool tooWide = bigWidth && charWidth >= 2 * _fontWidth;
            bool smallWidth = _fixedFont && c && charWidth < _fontWidth;
            CharacterColor currentForeground = _image[loc(x, y)].foregroundColor;
            CharacterColor currentBackground = _image[loc(x, y)].backgroundColor;
            quint8 currentRendition = _image[loc(x, y)].rendition;
            
            quint32 nxtC = 0;
            bool nxtDoubleWidth = false;
            int nxtCharWidth = 0;
            while (x + len <= rlx &&
                        _image[loc(x + len, y)].foregroundColor == currentForeground &&
                        _image[loc(x + len, y)].backgroundColor == currentBackground &&
                        _image[loc(x + len, y)].rendition == currentRendition &&
                        (nxtDoubleWidth = (_image[qMin(loc(x+len,y)+1,_imageSize)].character == 0)) == doubleWidth &&
                        !smallWidth &&
                        !(_fixedFont && (nxtC = _image[loc(x+len,y)].character) && (nxtCharWidth = fm.horizontalAdvance(QString::fromWCharArray((const wchar_t *)(&nxtC), 1))) < _fontWidth) &&
                        !bigWidth &&
                        !(_fixedFont && !nxtDoubleWidth && nxtC && nxtCharWidth > _fontWidth) &&
                        isLineChar(_image[loc(x+len,y)]) == lineDraw) // Assignment!
            {
                c = _image[loc(x+len,y)].character;
                if (_image[loc(x+len,y)].rendition & RE_EXTENDED_CHAR) {
                    // sequence of characters
                    ushort extendedCharLength = 0;
                    const uint* chars = ExtendedCharTable::instance.lookupExtendedChar(c, extendedCharLength);
                    if (chars) {
                        Q_ASSERT(extendedCharLength > 1);
                        bufferSize += extendedCharLength - 1;
                        unistr.resize(bufferSize);
                        for ( int index = 0 ; index < extendedCharLength ; index++ ) {
                            Q_ASSERT( p < bufferSize );
                            unistr[p++] = chars[index];
                        }
                    }
                } else {
                    // single character
                    if (c) {
                        Q_ASSERT( p < bufferSize );
                        unistr[p++] = c; //fontMap(c);
                    }
                }
                if (doubleWidth) // assert((_image[loc(x+len,y)+1].character == 0)), see
                                                 // above if condition
                    len++;         // Skip trailing part of multi-column character
                len++;
            }
            if ((x + len < _usedColumns) && (!_image[loc(x + len, y)].character))
                len++; // Adjust for trailing part of multi-column character

            bool save__fixedFont = _fixedFont;
            if (lineDraw)
                _fixedFont = false;
            unistr.resize(p);

            // Create a text scaling matrix for double width and double height lines.
            QTransform textScale;

            if (y < _lineProperties.size()) {
                if (_lineProperties[y] & LINE_DOUBLEWIDTH)
                    textScale.scale(2, 1);

                if (_lineProperties[y] & LINE_DOUBLEHEIGHT)
                    textScale.scale(1, 2);
            }

            // Apply text scaling matrix.
            paint.setWorldTransform(textScale, true);

            // calculate the area in which the text will be drawn
            QRect textArea = calculateTextArea(tLx, tLy, x, y, len);

            // move the calculated area to take account of scaling applied to the
            // painter. the position of the area from the origin (0,0) is scaled by
            // the opposite of whatever transformation has been applied to the
            // painter.  this ensures that painting does actually start from
            // textArea.topLeft() (instead of textArea.topLeft() * painter-scale)
            textArea.moveTopLeft(textScale.inverted().map(textArea.topLeft()));

            // paint text fragment
            drawTextFragment(paint, textArea, unistr, &_image[loc(x, y)], tooWide, _screenWindow->isSelected(x, y));

            _fixedFont = save__fixedFont;

            // reset back to single-width, single-height _lines
            paint.setWorldTransform(textScale.inverted(), true);

            if (y < _lineProperties.size() - 1) {
                // double-height _lines are represented by two adjacent _lines
                // containing the same characters
                // both _lines will have the LINE_DOUBLEHEIGHT attribute.
                // If the current line has the LINE_DOUBLEHEIGHT attribute,
                // we can therefore skip the next line
                if (_lineProperties[y] & LINE_DOUBLEHEIGHT)
                    y++;
            }

            x += len - 1;
        }
    }
}

void TerminalDisplay::blinkEvent() {
    if (!_allowBlinkingText)
        return;

    _blinking = !_blinking;

    // TODO:  Optimize to only repaint the areas of the widget
    //  where there is blinking text
    //  rather than repainting the whole widget.
    update();
}

QRect TerminalDisplay::imageToWidget(const QRect &imageArea) const {
    QRect result;
    result.setLeft(_leftMargin + _fontWidth * imageArea.left());
    result.setTop(_topMargin + _fontHeight * imageArea.top());
    result.setWidth(_fontWidth * imageArea.width());
    result.setHeight(_fontHeight * imageArea.height());

    return result;
}

void TerminalDisplay::updateCursor() {
    QRect cursorRect = imageToWidget(QRect(cursorPosition(), QSize(1, 1)));
    update(cursorRect);
}

void TerminalDisplay::blinkCursorEvent() {
    _cursorBlinking = !_cursorBlinking;
    updateCursor();
}


void TerminalDisplay::resizeEvent(QResizeEvent *) {
    updateImageSize();
    processFilters();
}

void TerminalDisplay::propagateSize() {
    if (_isFixedSize) {
        setSize(_columns, _lines);
        QWidget::setFixedSize(sizeHint());
        parentWidget()->adjustSize();
        parentWidget()->setFixedSize(parentWidget()->sizeHint());
        return;
    }
    if (_image)
        updateImageSize();
}

void TerminalDisplay::updateImageSize() {
    Character *oldimg = _image;
    int oldlin = _lines;
    int oldcol = _columns;

    makeImage();

    // copy the old image to reduce flicker
    int lines = qMin(oldlin, _lines);
    int columns = qMin(oldcol, _columns);

    if (oldimg) {
        for (int line = 0; line < lines; line++) {
            memcpy((void *)&_image[_columns * line], (void *)&oldimg[oldcol * line],
                         columns * sizeof(Character));
        }
        delete[] oldimg;
    }

    if (_screenWindow)
        _screenWindow->setWindowLines(_lines);

    _resizing = (oldlin != _lines) || (oldcol != _columns);

    if (_resizing) {
        if (_showResizeNotificationEnabled)
            showResizeNotification();
        emit changedContentSizeSignal(_contentHeight, _contentWidth); // expose resizeEvent
        emit changedContentCountSignal(_lines, _columns);
    }

    _resizing = false;
}

// showEvent and hideEvent are reimplemented here so that it appears to other
// classes that the display has been resized when the display is hidden or
// shown.
//
// TODO: Perhaps it would be better to have separate signals for show and hide
// instead of using the same signal as the one for a content size change
void TerminalDisplay::showEvent(QShowEvent *) {
    emit changedContentSizeSignal(_contentHeight, _contentWidth);
}

void TerminalDisplay::hideEvent(QHideEvent *) {
    emit changedContentSizeSignal(_contentHeight, _contentWidth);
}

void TerminalDisplay::scrollBarPositionChanged(int) {
    if (!_screenWindow)
        return;

    _screenWindow->scrollTo(_scrollBar->value());

    // if the thumb has been moved to the bottom of the _scrollBar then set
    // the display to automatically track new output,
    // that is, scroll down automatically
    // to how new _lines as they are added
    const bool atEndOfOutput = (_scrollBar->value() == _scrollBar->maximum());
    _screenWindow->setTrackOutput(atEndOfOutput);

    updateImage();
}

void TerminalDisplay::setScroll(int cursor, int slines) {
    // update _scrollBar if the range or value has changed,
    // otherwise return
    //
    // setting the range or value of a _scrollBar will always trigger
    // a repaint, so it should be avoided if it is not necessary
    if (_scrollBar->minimum() == 0 &&
            _scrollBar->maximum() == (slines - _lines) &&
            _scrollBar->value() == cursor) {
        return;
    }

    disconnect(_scrollBar, &QScrollBar::valueChanged, this,
                         &TerminalDisplay::scrollBarPositionChanged);
    _scrollBar->setRange(0, slines - _lines);
    _scrollBar->setSingleStep(1);
    _scrollBar->setPageStep(_lines);
    _scrollBar->setValue(cursor);
    connect(_scrollBar, &QScrollBar::valueChanged, this,
                    &TerminalDisplay::scrollBarPositionChanged);
}

void TerminalDisplay::scrollToEnd() {
    disconnect(_scrollBar, &QScrollBar::valueChanged, this,
                         &TerminalDisplay::scrollBarPositionChanged);
    _scrollBar->setValue(_scrollBar->maximum());
    connect(_scrollBar, &QScrollBar::valueChanged, this,
                    &TerminalDisplay::scrollBarPositionChanged);

    _screenWindow->scrollTo(_scrollBar->value() + 1);
    _screenWindow->setTrackOutput(_screenWindow->atEndOfOutput());
}

void TerminalDisplay::setScrollBarPosition(
        QTermWidget::ScrollBarPosition position) {
    if (_scrollbarLocation == position)
        return;

    if (position == QTermWidget::NoScrollBar)
        _scrollBar->hide();
    else
        _scrollBar->show();

    _topMargin = _leftMargin = 1;
    _scrollbarLocation = position;

    propagateSize();
    update();
}

void TerminalDisplay::mousePressEvent(QMouseEvent *ev) {
    emit mousePressEventForwarded(ev);

    if (_possibleTripleClick && (ev->button() == Qt::LeftButton)) {
        mouseTripleClickEvent(ev);
        return;
    }

    if (!contentsRect().contains(ev->pos()))
        return;

    if (!_screenWindow)
        return;

    int charLine;
    int charColumn;
    getCharacterPosition(ev->pos(), charLine, charColumn);
    QPoint pos = QPoint(charColumn, charLine);

    if (ev->button() == Qt::LeftButton) {
        _lineSelectionMode = false;
        _wordSelectionMode = false;

        emit isBusySelecting(true); // Keep it steady...
        // Drag only when the Control key is hold
        bool selected = false;

        // The receiver of the testIsSelected() signal will adjust
        // 'selected' accordingly.
        // emit testIsSelected(pos.x(), pos.y(), selected);

        selected = _screenWindow->isSelected(pos.x(), pos.y());

        if ((!_ctrlDrag || ev->modifiers() & Qt::ControlModifier) && selected) {
            // The user clicked inside selected text
            if ((_mouseMarks) && (ev->modifiers() & Qt::ShiftModifier)) {
                _screenWindow->clearSelection();
                if (shiftSelectionStartX == -1 && shiftSelectionStartY == -1) {
                    shiftSelectionStartX = pos.x();
                    shiftSelectionStartY = pos.y();
                } else {
                    _screenWindow->setSelectionStart(shiftSelectionStartX,
                                                     shiftSelectionStartY,
                                                     ev->modifiers() & Qt::AltModifier);
                    _screenWindow->setSelectionEnd(pos.x(), pos.y());
                }
            } else {
                shiftSelectionStartX = -1;
                shiftSelectionStartY = -1;
                dragInfo.state = diPending;
                dragInfo.start = ev->pos();
            }
        } else {
            // No reason to ever start a drag event
            dragInfo.state = diNone;

            _preserveLineBreaks = !((ev->modifiers() & Qt::ControlModifier) &&
                                                !(ev->modifiers() & Qt::AltModifier));
            _columnSelectionMode = (ev->modifiers() & Qt::AltModifier) &&
                                                (ev->modifiers() & Qt::ControlModifier);

            if (_mouseMarks) {
                if (ev->modifiers() & Qt::ShiftModifier) {
                    if (_screenWindow->isClearSelection()) {
                        // check
                        if (shiftSelectionStartX == -1 && shiftSelectionStartY == -1) {
                            shiftSelectionStartX = pos.x();
                            shiftSelectionStartY = pos.y();
                        } else {
                            _screenWindow->setSelectionStart(
                                    shiftSelectionStartX, shiftSelectionStartY,
                                    ev->modifiers() & Qt::AltModifier);
                            _screenWindow->setSelectionEnd(pos.x(), pos.y());
                        }
                    } else {
                        _screenWindow->clearSelection();
                        if (shiftSelectionStartX == -1 && shiftSelectionStartY == -1) {
                            shiftSelectionStartX = pos.x();
                            shiftSelectionStartY = pos.y();
                        } else {
                            _screenWindow->setSelectionStart(
                                    shiftSelectionStartX, shiftSelectionStartY,
                                    ev->modifiers() & Qt::AltModifier);
                            _screenWindow->setSelectionEnd(pos.x(), pos.y());
                        }
                    }
                } else {
                    _screenWindow->clearSelection();
                    shiftSelectionStartX = -1;
                    shiftSelectionStartY = -1;
                    // emit clearSelectionSignal();
                    pos.ry() += _scrollBar->value();
                    _iPntSel = _pntSel = pos;
                    _actSel = 1; // left mouse button pressed but nothing selected yet.
                }
            } else {
                if (ev->modifiers() & Qt::ShiftModifier) {
                    _screenWindow->clearSelection();

                    // emit clearSelectionSignal();
                    pos.ry() += _scrollBar->value();
                    _iPntSel = _pntSel = pos;
                    _actSel = 1; // left mouse button pressed but nothing selected yet.
                } else {
                    emit mouseSignal(
                            0, charColumn + 1,
                            charLine + 1 + _scrollBar->value() - _scrollBar->maximum(), 0);
                }
            }

            if (ev->modifiers() & Qt::ControlModifier) {
                Filter::HotSpot *spot = _filterChain->hotSpotAt(charLine, charColumn);
                if (spot && spot->type() == Filter::HotSpot::Link) {
                    if (spot->hasClickAction()) {
                        spot->clickAction();
                    }
                }
            }
        }
    } else if (ev->button() == Qt::MiddleButton) {
        if (_mouseMarks || (ev->modifiers() & Qt::ShiftModifier))
            emitSelection(true, ev->modifiers() & Qt::ControlModifier);
        else
            emit mouseSignal(
                    1, charColumn + 1,
                    charLine + 1 + _scrollBar->value() - _scrollBar->maximum(), 0);
    } else if (ev->button() == Qt::RightButton) {
        if (_mouseMarks || (ev->modifiers() & Qt::ShiftModifier))
            emit configureRequest(ev->pos());
        else
            emit mouseSignal(
                    2, charColumn + 1,
                    charLine + 1 + _scrollBar->value() - _scrollBar->maximum(), 0);
    }
}

QList<QAction *> TerminalDisplay::filterActions(const QPoint &position) {
    int charLine, charColumn;
    getCharacterPosition(position, charLine, charColumn);

    Filter::HotSpot *spot = _filterChain->hotSpotAt(charLine, charColumn);

    return spot ? spot->actions() : QList<QAction *>();
}

void TerminalDisplay::hideStaleMouse() const
{
    if (gs_deadSpot.x() > -1) // we already have a dead spot
        return;
    if (gs_futureDeadSpot.x() < 0) // that's not expected nor gonna end well
        return;
    if (!underMouse()) // we don't care about the mouse
        return;
    if (QApplication::activeWindow() && QApplication::activeWindow() != window()) // some other app window has the focus
        return;
    if (_scrollBar->underMouse()) // the mouse is over the scrollbar
        return;
    gs_deadSpot = gs_futureDeadSpot;
    QApplication::setOverrideCursor(Qt::BlankCursor);
}

void TerminalDisplay::autoHideMouseAfter(int delay)
{
    if (delay > -1 && !_hideMouseTimer)
    {
        _hideMouseTimer = std::make_shared<QTimer>();
        _hideMouseTimer->setSingleShot(true);
    }
    if ((_mouseAutohideDelay < 0) == (delay < 0))
    {
        _mouseAutohideDelay = delay;
        return;
    }
    if (delay > -1)
        connect(_hideMouseTimer.get(), &QTimer::timeout, this, &TerminalDisplay::hideStaleMouse);
    else if (_hideMouseTimer)
        disconnect(_hideMouseTimer.get(), &QTimer::timeout, this, &TerminalDisplay::hideStaleMouse);
    _mouseAutohideDelay = delay;
}

void TerminalDisplay::mouseMoveEvent(QMouseEvent *ev) {
    // unclutter
    if (_mouseAutohideDelay > -1) {
        if (gs_deadSpot.x() > -1 && (ev->pos() - gs_deadSpot).manhattanLength() > 8)
        {
            gs_deadSpot = QPoint(-1,-1);
            QApplication::restoreOverrideCursor();
        }
        gs_futureDeadSpot = ev->position().toPoint();
        Q_ASSERT(_hideMouseTimer);
        _hideMouseTimer->start(_mouseAutohideDelay);
    }

    int charLine = 0;
    int charColumn = 0;
    int leftMargin = _leftBaseMargin +
                    ((_scrollbarLocation == QTermWidget::ScrollBarLeft &&
                        !_scrollBar->style()->styleHint(
                                QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
                            ? _scrollBar->width()
                            : 0);

    getCharacterPosition(ev->position().toPoint(), charLine, charColumn);

    // handle filters
    // change link hot-spot appearance on mouse-over
    Filter::HotSpot *spot = _filterChain->hotSpotAt(charLine, charColumn);
    if (spot && spot->type() == Filter::HotSpot::Link) {
        QRegion previousHotspotArea = _mouseOverHotspotArea;
        _mouseOverHotspotArea = QRegion();
        QRect r;
        if (spot->startLine() == spot->endLine()) {
            r.setCoords(spot->startColumn() * _fontWidth + leftMargin,
                                    spot->startLine() * _fontHeight + _topBaseMargin,
                                    spot->endColumn() * _fontWidth + leftMargin,
                                    (spot->endLine() + 1) * _fontHeight - 1 + _topBaseMargin);
            _mouseOverHotspotArea |= r;
        } else {
            r.setCoords(spot->startColumn() * _fontWidth + leftMargin,
                                    spot->startLine() * _fontHeight + _topBaseMargin,
                                    _columns * _fontWidth - 1 + leftMargin,
                                    (spot->startLine() + 1) * _fontHeight + _topBaseMargin);
            _mouseOverHotspotArea |= r;
            for (int line = spot->startLine() + 1; line < spot->endLine(); line++) {
                r.setCoords(0 * _fontWidth + leftMargin,
                                        line * _fontHeight + _topBaseMargin,
                                        _columns * _fontWidth + leftMargin,
                                        (line + 1) * _fontHeight + _topBaseMargin);
                _mouseOverHotspotArea |= r;
            }
            r.setCoords(0 * _fontWidth + leftMargin,
                                    spot->endLine() * _fontHeight + _topBaseMargin,
                                    spot->endColumn() * _fontWidth + leftMargin,
                                    (spot->endLine() + 1) * _fontHeight + _topBaseMargin);
            _mouseOverHotspotArea |= r;
        }

        update(_mouseOverHotspotArea | previousHotspotArea);
        if (_mouseOverHotspotArea.contains(ev->pos())) {
            if (spot && spot->type() == Filter::HotSpot::Link &&
                    spot->hasClickAction()) {
                QPoint globalPos = mapToGlobal(ev->pos());
                QToolTip::showText(globalPos, spot->clickActionToolTip());
                if (!_ctrlDrag && ev->modifiers() & Qt::ControlModifier) {
                    setCursor(QCursor(Qt::PointingHandCursor));
                } else {
                    setCursor(QCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor));
                }
            } else {
                setCursor(QCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor));
            }
        } else {
            QToolTip::hideText();
            setCursor(QCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor));
        }
    } else if (!_mouseOverHotspotArea.isEmpty()) {
        update(_mouseOverHotspotArea);
        // set hotspot area to an invalid rectangle
        _mouseOverHotspotArea = QRegion();
        QToolTip::hideText();
        setCursor(QCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor));
    }

    // for auto-hiding the cursor, we need mouseTracking
    if (ev->buttons() == Qt::NoButton)
        return;

    // if the terminal is interested in mouse movements
    // then emit a mouse movement signal, unless the shift
    // key is being held down, which overrides this.
    if (!_mouseMarks && !(ev->modifiers() & Qt::ShiftModifier)) {
        int button = 3;
        if (ev->buttons() & Qt::LeftButton)
            button = 0;
        if (ev->buttons() & Qt::MiddleButton)
            button = 1;
        if (ev->buttons() & Qt::RightButton)
            button = 2;

        emit mouseSignal(button, charColumn + 1,
                        charLine + 1 + _scrollBar->value() - _scrollBar->maximum(),
                        1);

        return;
    }

    if (dragInfo.state == diPending) {
        // we had a mouse down, but haven't confirmed a drag yet
        // if the mouse has moved sufficiently, we will confirm

        //   int distance = KGlobalSettings::dndEventDelay();
        int distance = QApplication::startDragDistance();
        if (ev->position().x() > dragInfo.start.x() + distance ||
                ev->position().x() < dragInfo.start.x() - distance ||
                ev->position().y() > dragInfo.start.y() + distance ||
                ev->position().y() < dragInfo.start.y() - distance) {
            // we've left the drag square, we can start a real drag operation now
            emit isBusySelecting(false); // Ok.. we can breath again.

            _screenWindow->clearSelection();
            doDrag();
        }
        return;
    } else if (dragInfo.state == diDragging) {
        // this isn't technically needed because mouseMoveEvent is suppressed during
        // Qt drag operations, replaced by dragMoveEvent
        return;
    }

    if (_actSel == 0)
        return;

    // don't extend selection while pasting
    if (ev->buttons() & Qt::MiddleButton)
        return;

    extendSelection(ev->position().toPoint());
}

void TerminalDisplay::extendSelection(const QPoint &position) {
    QPoint pos = position;

    if (!_screenWindow)
        return;

    // if ( !contentsRect().contains(ev->pos()) ) return;
    QPoint tL = contentsRect().topLeft();
    int tLx = tL.x();
    int tLy = tL.y();
    int scroll = _scrollBar->value();

    // we're in the process of moving the mouse with the left button pressed
    // the mouse cursor will kept caught within the bounds of the text in
    // this widget.

    int linesBeyondWidget = 0;

    QRect textBounds(tLx + _leftMargin, tLy + _topMargin,
                     _usedColumns * _fontWidth - 1, _usedLines * _fontHeight - 1);

    // Adjust position within text area bounds.
    QPoint oldpos = pos;

    pos.setX(qBound(textBounds.left(), pos.x(), textBounds.right()));
    pos.setY(qBound(textBounds.top(), pos.y(), textBounds.bottom()));

    if (oldpos.y() > textBounds.bottom()) {
        linesBeyondWidget = (oldpos.y() - textBounds.bottom()) / _fontHeight;
        _scrollBar->setValue(_scrollBar->value() + linesBeyondWidget +
                                                 1); // scrollforward
    }
    if (oldpos.y() < textBounds.top()) {
        linesBeyondWidget = (textBounds.top() - oldpos.y()) / _fontHeight;
        _scrollBar->setValue(_scrollBar->value() - linesBeyondWidget -
                                                 1); // history
    }

    int charColumn = 0;
    int charLine = 0;
    getCharacterPosition(pos, charLine, charColumn);

    QPoint here = QPoint(
            charColumn,
            charLine); // QPoint((pos.x()-tLx-_leftMargin+(_fontWidth/2))/_fontWidth,(pos.y()-tLy-_topMargin)/_fontHeight);
    QPoint ohere;
    QPoint _iPntSelCorr = _iPntSel;
    _iPntSelCorr.ry() -= _scrollBar->value();
    QPoint _pntSelCorr = _pntSel;
    _pntSelCorr.ry() -= _scrollBar->value();
    bool swapping = false;

    if (_wordSelectionMode) {
        // Extend to word boundaries
        int i;
        QChar selClass;

        bool left_not_right =
                (here.y() < _iPntSelCorr.y() ||
                 (here.y() == _iPntSelCorr.y() && here.x() < _iPntSelCorr.x()));
        bool old_left_not_right = (_pntSelCorr.y() < _iPntSelCorr.y() ||
                                    (_pntSelCorr.y() == _iPntSelCorr.y() &&
                                    _pntSelCorr.x() < _iPntSelCorr.x()));
        swapping = left_not_right != old_left_not_right;

        // Find left (left_not_right ? from here : from start)
        QPoint left = left_not_right ? here : _iPntSelCorr;
        i = loc(left.x(), left.y());
        if (i >= 0 && i <= _imageSize) {
            selClass = charClass(_image[i]);
            while (
                    ((left.x() > 0) ||
                     (left.y() > 0 && (_lineProperties[left.y() - 1] & LINE_WRAPPED))) &&
                    charClass(_image[i-1]) == selClass ) {
                i--;
                if (left.x() > 0)
                    left.rx()--;
                else {
                    left.rx() = _usedColumns - 1;
                    left.ry()--;
                }
            }
        }

        // Find left (left_not_right ? from start : from here)
        QPoint right = left_not_right ? _iPntSelCorr : here;
        i = loc(right.x(), right.y());
        if (i >= 0 && i <= _imageSize) {
            selClass = charClass(_image[i]);
            while (((right.x() < _usedColumns - 1) ||
                            (right.y() < _usedLines - 1 &&
                             (_lineProperties[right.y()] & LINE_WRAPPED))) &&
                            charClass(_image[i+1]) == selClass) {
                i++;
                if (right.x() < _usedColumns - 1)
                    right.rx()++;
                else {
                    right.rx() = 0;
                    right.ry()++;
                }
            }
        }

        // Pick which is start (ohere) and which is extension (here)
        if (left_not_right) {
            here = left;
            ohere = right;
        } else {
            here = right;
            ohere = left;
        }
        ohere.rx()++;
    }

    if (_lineSelectionMode) {
        // Extend to complete line
        bool above_not_below = (here.y() < _iPntSelCorr.y());

        QPoint above = above_not_below ? here : _iPntSelCorr;
        QPoint below = above_not_below ? _iPntSelCorr : here;

        while (above.y() > 0 && (_lineProperties[above.y() - 1] & LINE_WRAPPED))
            above.ry()--;
        while (below.y() < _usedLines - 1 &&
                     (_lineProperties[below.y()] & LINE_WRAPPED))
            below.ry()++;

        above.setX(0);
        below.setX(_usedColumns - 1);

        // Pick which is start (ohere) and which is extension (here)
        if (above_not_below) {
            here = above;
            ohere = below;
        } else {
            here = below;
            ohere = above;
        }

        QPoint newSelBegin = QPoint(ohere.x(), ohere.y());
        swapping = !(_tripleSelBegin == newSelBegin);
        _tripleSelBegin = newSelBegin;

        ohere.rx()++;
    }

    int offset = 0;
    if (!_wordSelectionMode && !_lineSelectionMode) {
        int i;
        QChar selClass;

        bool left_not_right =
                (here.y() < _iPntSelCorr.y() ||
                 (here.y() == _iPntSelCorr.y() && here.x() < _iPntSelCorr.x()));
        bool old_left_not_right = (_pntSelCorr.y() < _iPntSelCorr.y() ||
                                    (_pntSelCorr.y() == _iPntSelCorr.y() &&
                                    _pntSelCorr.x() < _iPntSelCorr.x()));
        swapping = left_not_right != old_left_not_right;

        // Find left (left_not_right ? from here : from start)
        QPoint left = left_not_right ? here : _iPntSelCorr;

        // Find left (left_not_right ? from start : from here)
        QPoint right = left_not_right ? _iPntSelCorr : here;
        if (right.x() > 0 && !_columnSelectionMode) {
            i = loc(right.x(), right.y());
            if (i >= 0 && i <= _imageSize) {
                selClass = charClass(_image[i-1]);
                /* if (selClass == ' ')
                 {
                    while ( right.x() < _usedColumns-1 && charClass(_image[i+1]) == selClass && (right.y()<_usedLines-1) &&
                                    !(_lineProperties[right.y()] & LINE_WRAPPED))
                     { i++; right.rx()++; }
                     if (right.x() < _usedColumns-1)
                         right = left_not_right ? _iPntSelCorr : here;
                     else
                         right.rx()++;  // will be balanced later because of offset=-1;
                 }*/
            }
        }

        // Pick which is start (ohere) and which is extension (here)
        if (left_not_right) {
            here = left;
            ohere = right;
            offset = 0;
        } else {
            here = right;
            ohere = left;
            offset = -1;
        }
    }

    if ((here == _pntSelCorr) && (scroll == _scrollBar->value()))
        return; // not moved

    if (here == ohere)
        return; // It's not left, it's not right.

    if (_actSel < 2 || swapping) {
        if (_columnSelectionMode && !_lineSelectionMode && !_wordSelectionMode) {
            _screenWindow->setSelectionStart(ohere.x(), ohere.y(), true);
        } else {
            _screenWindow->setSelectionStart(ohere.x() - 1 - offset, ohere.y(), false);
        }
    }

    _actSel = 2; // within selection
    _pntSel = here;
    _pntSel.ry() += _scrollBar->value();

    if (_columnSelectionMode && !_lineSelectionMode && !_wordSelectionMode) {
        _screenWindow->setSelectionEnd(here.x(), here.y());
    } else {
        _screenWindow->setSelectionEnd(here.x() + offset, here.y());
    }
}

void TerminalDisplay::mouseReleaseEvent(QMouseEvent *ev) {
    if (!_screenWindow)
        return;

    int charLine;
    int charColumn;
    getCharacterPosition(ev->pos(), charLine, charColumn);

    if (ev->button() == Qt::LeftButton) {
        emit isBusySelecting(false);
        if (dragInfo.state == diPending) {
            // We had a drag event pending but never confirmed.  Kill selection
            _screenWindow->clearSelection();
            // emit clearSelectionSignal();
        } else {
            if (_actSel > 1) {
                setSelection(_screenWindow->selectedText(_preserveLineBreaks));
            }

            _actSel = 0;

            // FIXME: emits a release event even if the mouse is
            //        outside the range. The procedure used in `mouseMoveEvent'
            //        applies here, too.

            if (!_mouseMarks && !(ev->modifiers() & Qt::ShiftModifier))
                emit mouseSignal(
                        0, charColumn + 1,
                        charLine + 1 + _scrollBar->value() - _scrollBar->maximum(), 2);
        }
        dragInfo.state = diNone;
    }

    if (!_mouseMarks && ((ev->button() == Qt::RightButton &&
                                                !(ev->modifiers() & Qt::ShiftModifier)) ||
                                             ev->button() == Qt::MiddleButton)) {
        emit mouseSignal(ev->button() == Qt::MiddleButton ? 1 : 2, charColumn + 1,
                                         charLine + 1 + _scrollBar->value() - _scrollBar->maximum(),
                                         2);
    }
}

void TerminalDisplay::getCharacterPosition(const QPointF &widgetPoint,
                                           int &line, int &column) const {
    line = (widgetPoint.y() - contentsRect().top() - _topMargin) / _fontHeight;
    if (line < 0)
        line = 0;
    if (line >= _usedLines)
        line = _usedLines - 1;

    int x =
            widgetPoint.x() + _fontWidth / 2 - contentsRect().left() - _leftMargin;
    if (_fixedFont)
        column = x / _fontWidth;
    else {
        column = 0;
        while (column + 1 < _usedColumns && x > textWidth(0, column + 1, line))
            column++;
    }

    if (column < 0)
        column = 0;

    // the column value returned can be equal to _usedColumns, which
    // is the position just after the last character displayed in a line.
    //
    // this is required so that the user can select characters in the right-most
    // column (or left-most for right-to-left input)
    if (column > _usedColumns)
        column = _usedColumns;
}

void TerminalDisplay::updateFilters() {
    if (!_screenWindow)
        return;

    processFilters();
}

void TerminalDisplay::updateLineProperties() {
    if (!_screenWindow)
        return;

    _lineProperties = _screenWindow->getLineProperties();
}

void TerminalDisplay::mouseDoubleClickEvent(QMouseEvent *ev) {
    if (ev->button() != Qt::LeftButton)
        return;
    if (!_screenWindow)
        return;

    int charLine = 0;
    int charColumn = 0;

    getCharacterPosition(ev->pos(), charLine, charColumn);

    QPoint pos(charColumn, charLine);

    // pass on double click as two clicks.
    if (!_mouseMarks && !(ev->modifiers() & Qt::ShiftModifier)) {
        // Send just _ONE_ click event, since the first click of the double click
        // was already sent by the click handler
        emit mouseSignal(0, pos.x() + 1,pos.y() + 1 + _scrollBar->value() - _scrollBar->maximum(), 0); // left button
        return;
    }

    _screenWindow->clearSelection();
    QPoint bgnSel = pos;
    QPoint endSel = pos;
    int i = loc(bgnSel.x(), bgnSel.y());
    _iPntSel = bgnSel;
    _iPntSel.ry() += _scrollBar->value();

    _wordSelectionMode = true;

    // find word boundaries...
    QChar selClass = charClass(_image[i]);
    {
        // find the start of the word
        int x = bgnSel.x();
        while (((x > 0) || (bgnSel.y() > 0 && (_lineProperties[bgnSel.y() - 1] & LINE_WRAPPED))) &&
                     charClass(_image[i-1]) == selClass ) {
            i--;
            if (x > 0)
                x--;
            else {
                x = _usedColumns - 1;
                bgnSel.ry()--;
            }
        }

        bgnSel.setX(x);
        _screenWindow->setSelectionStart(bgnSel.x(), bgnSel.y(), false);

        // find the end of the word
        i = loc(endSel.x(), endSel.y());
        x = endSel.x();
        while (((x < _usedColumns - 1) ||
                (endSel.y() < _usedLines - 1 &&
                (_lineProperties[endSel.y()] & LINE_WRAPPED))) &&
                charClass(_image[i+1]) == selClass ) {
            i++;
            if (x < _usedColumns - 1)
                x++;
            else {
                x = 0;
                endSel.ry()++;
            }
        }

        endSel.setX(x);

        // In word selection mode don't select @ (64) if at end of word.
        if (QChar(_image[i].character) == QLatin1Char('@') &&
            endSel.x() - bgnSel.x() > 0 &&
            (_image[i].rendition & RE_EXTENDED_CHAR) == 0) {
            endSel.setX( x - 1 );
        }

        _actSel = 2; // within selection

        _screenWindow->setSelectionEnd(endSel.x(), endSel.y());

        setSelection(_screenWindow->selectedText(_preserveLineBreaks));
    }

    _possibleTripleClick = true;

    QTimer::singleShot(QApplication::doubleClickInterval(), this, &TerminalDisplay::tripleClickTimeout);
}

void TerminalDisplay::wheelEvent(QWheelEvent *ev) {
    if (ev->angleDelta().y() == 0)
        return;

    if (_mouseMarks && _scrollBar->maximum() > 0) {
        // If the program running in the terminal is not interested in
        // Mouse events, send the event to the scrollbar if the slider
        // has room to move
        _scrollBar->event(ev);
    } else if (_mouseMarks && !_isPrimaryScreen) {
        // assume that each Up / Down key event will cause the terminal application
        // to scroll by one line.
        //
        // to get a reasonable scrolling speed, scroll by one line for every 5
        // degrees of mouse wheel rotation.  Mouse wheels typically move in steps of
        // 15 degrees, giving a scroll of 3 lines
        int key = ev->angleDelta().y() > 0 ? Qt::Key_Up : Qt::Key_Down;

        // QWheelEvent::angleDelta().y() gives rotation in eighths of a degree
        int wheelDegrees = ev->angleDelta().y() / 8;
        int linesToScroll = abs(wheelDegrees) / 5;

        QKeyEvent keyScrollEvent(QEvent::KeyPress, key, Qt::NoModifier);

        for (int i = 0; i < linesToScroll; i++)
            emit keyPressedSignal(&keyScrollEvent, false);
    } else if (!_mouseMarks) {
        // terminal program wants notification of mouse activity
        int charLine;
        int charColumn;
        getCharacterPosition(ev->position(), charLine, charColumn);

        emit mouseSignal(ev->angleDelta().y() > 0 ? 4 : 5, charColumn + 1,
                        charLine + 1 + _scrollBar->value() - _scrollBar->maximum(), 0);
    }
}

void TerminalDisplay::tripleClickTimeout() { _possibleTripleClick = false; }

void TerminalDisplay::mouseTripleClickEvent(QMouseEvent *ev) {
    if (!_screenWindow)
        return;

    int charLine;
    int charColumn;
    getCharacterPosition(ev->pos(), charLine, charColumn);
    _iPntSel = QPoint(charColumn, charLine);

    _screenWindow->clearSelection();

    _lineSelectionMode = true;
    _wordSelectionMode = false;

    _actSel = 2;                // within selection
    emit isBusySelecting(true); // Keep it steady...

    while (_iPntSel.y() > 0 && (_lineProperties[_iPntSel.y() - 1] & LINE_WRAPPED))
        _iPntSel.ry()--;

    if (_tripleClickMode == SelectForwardsFromCursor) {
        // find word boundary start
        int i = loc(_iPntSel.x(), _iPntSel.y());
        QChar selClass = charClass(_image[i]);
        int x = _iPntSel.x();

        while (((x > 0) || (_iPntSel.y() > 0 &&
                (_lineProperties[_iPntSel.y() - 1] & LINE_WRAPPED))) &&
                charClass(_image[i-1]) == selClass) {
            i--;
            if (x > 0)
                x--;
            else {
                x = _columns - 1;
                _iPntSel.ry()--;
            }
        }

        _screenWindow->setSelectionStart(x, _iPntSel.y(), false);
        _tripleSelBegin = QPoint(x, _iPntSel.y());
    } else if (_tripleClickMode == SelectWholeLine) {
        _screenWindow->setSelectionStart(0, _iPntSel.y(), false);
        _tripleSelBegin = QPoint(0, _iPntSel.y());
    }

    while (_iPntSel.y() < _lines - 1 &&
                 (_lineProperties[_iPntSel.y()] & LINE_WRAPPED))
        _iPntSel.ry()++;

    _screenWindow->setSelectionEnd(_columns - 1, _iPntSel.y());

    setSelection(_screenWindow->selectedText(_preserveLineBreaks));

    _iPntSel.ry() += _scrollBar->value();
}

bool TerminalDisplay::focusNextPrevChild(bool next) {
    if (next)
        return false; // This disables changing the active part in konqueror
                                    // when pressing Tab
    return QWidget::focusNextPrevChild(next);
}

QChar TerminalDisplay::charClass(const Character &ch) const {
    if (ch.rendition & RE_EXTENDED_CHAR) {
        ushort extendedCharLength = 0;
        const uint* chars = ExtendedCharTable::instance.lookupExtendedChar(ch.character, extendedCharLength);
        if (chars && extendedCharLength > 0) {
            std::wstring str;
            for (ushort nchar = 0; nchar < extendedCharLength; nchar++) {
                str.push_back(chars[nchar]);
            }
            const QString s = QString::fromStdWString(str);
            if (_wordCharacters.contains(s, Qt::CaseInsensitive))
                return QLatin1Char('a');
            bool allLetterOrNumber = true;
            for (int i = 0; allLetterOrNumber && i < s.size(); ++i)
                allLetterOrNumber = s.at(i).isLetterOrNumber();
            return allLetterOrNumber ? QLatin1Char('a') : s.at(0);
        }
        return QChar(0);
    } else {
        if(ch.character > 0xffff) {
            return QLatin1Char('a');
        }
        const QChar qch(ch.character);
        if (qch.isSpace())
            return QLatin1Char(' ');
        if (qch.isLetterOrNumber() || _wordCharacters.contains(qch, Qt::CaseInsensitive ))
            return QLatin1Char('a');
        return qch;
    }
}

void TerminalDisplay::setWordCharacters(const QString &wc) {
    _wordCharacters = wc.toLatin1();
}

void TerminalDisplay::setUsesMouse(bool on) {
    if (_mouseMarks != on) {
        _mouseMarks = on;
        setCursor(_mouseMarks ? Qt::IBeamCursor : Qt::ArrowCursor);
        emit usesMouseChanged();
    }
}
bool TerminalDisplay::usesMouse() const { return _mouseMarks; }

void TerminalDisplay::usingPrimaryScreen(bool use) { _isPrimaryScreen = use; }

void TerminalDisplay::setBracketedPasteMode(bool on) {
    _bracketedPasteMode = on;
}
bool TerminalDisplay::bracketedPasteMode() const { return _bracketedPasteMode; }

#undef KeyPress

void TerminalDisplay::emitSelection(bool useXselection, bool appendReturn) {
    if (!_screenWindow)
        return;

    // Paste Clipboard by simulating keypress events
    QString text = QApplication::clipboard()->text(
            useXselection ? QClipboard::Selection : QClipboard::Clipboard);
    if (!text.isEmpty()) {
        text.replace(QLatin1String("\r\n"), QLatin1String("\n"));
        text.replace(QLatin1Char('\n'), QLatin1Char('\r'));

        if (_trimPastedTrailingNewlines) {
            text.replace(QRegularExpression(QStringLiteral("\\r+$")), QString());
        }

        if (_confirmMultilinePaste && text.contains(QLatin1Char('\r'))) {
            if (!multilineConfirmation(text)) {
                return;
            }
        }

        bracketText(text);

        // appendReturn is intentionally handled _after_ enclosing texts with
        // brackets as that feature is used to allow execution of commands
        // immediately after paste. Ref: https://bugs.kde.org/show_bug.cgi?id=16179
        // Ref:
        // https://github.com/KDE/konsole/commit/83d365f2ebfe2e659c1e857a2f5f247c556ab571
        if (appendReturn) {
            text.append(QLatin1Char('\r'));
        }

        QKeyEvent e(QEvent::KeyPress, 0, Qt::NoModifier, text);
        emit keyPressedSignal(&e, true); // expose as a big fat keypress event

        _screenWindow->clearSelection();

        switch (mMotionAfterPasting) {
        case MoveStartScreenWindow:
            // Temporarily stop tracking output, or pasting contents triggers
            // ScreenWindow::notifyOutputChanged() and the latter scrolls the
            // terminal to the last line. It will be re-enabled when needed
            // (e.g., scrolling to the last line).
            _screenWindow->setTrackOutput(false);
            _screenWindow->scrollTo(0);
            break;
        case MoveEndScreenWindow:
            scrollToEnd();
            break;
        case NoMoveScreenWindow:
            break;
        }
    }
}

void TerminalDisplay::bracketText(QString &text) const {
    if (bracketedPasteMode() && !_disabledBracketedPasteMode) {
        text.prepend(QLatin1String("\033[200~"));
        text.append(QLatin1String("\033[201~"));
    }
}

bool TerminalDisplay::multilineConfirmation(QString &text) {
    MultilineConfirmationMessageBox confirmation(messageParentWidget);
    confirmation.setWindowTitle(tr("Paste multiline text"));
    confirmation.setText(tr("Are you sure you want to paste this text?"));
    confirmation.setDetailedText(text);
    if (confirmation.exec() == QDialog::Accepted) {
        text = confirmation.getDetailedText();
        return true;
    }
    return false;
}

void TerminalDisplay::setSelection(const QString &t) {
    if (QApplication::clipboard()->supportsSelection()) {
        QApplication::clipboard()->setText(t, QClipboard::Selection);
    }
}

void TerminalDisplay::copyClipboard(QClipboard::Mode mode) {
    if (!_screenWindow)
        return;

    QString text = _screenWindow->selectedText(_preserveLineBreaks);
    if (!text.isEmpty())
        QApplication::clipboard()->setText(text, mode);
}

void TerminalDisplay::pasteClipboard() { emitSelection(false, false); }

void TerminalDisplay::pasteSelection() { emitSelection(true, false); }

void TerminalDisplay::selectAll() {
    if (!_screenWindow)
        return;

    _screenWindow->clearSelection();
    _screenWindow->setSelectionStart(0, 0, false);
    _screenWindow->setSelectionEnd(_columns - 1, _lines - 1);
    setSelection(_screenWindow->selectedText(_preserveLineBreaks));
}

void TerminalDisplay::setConfirmMultilinePaste(bool confirmMultilinePaste) {
    _confirmMultilinePaste = confirmMultilinePaste;
}

void TerminalDisplay::setTrimPastedTrailingNewlines(
        bool trimPastedTrailingNewlines) {
    _trimPastedTrailingNewlines = trimPastedTrailingNewlines;
}

void TerminalDisplay::setFlowControlWarningEnabled(bool enable) {
    _flowControlWarningEnabled = enable;

    // if the dialog is currently visible and the flow control warning has
    // been disabled then hide the dialog
    if (!enable)
        outputSuspended(false);
}

void TerminalDisplay::setMotionAfterPasting(MotionAfterPasting action) {
    mMotionAfterPasting = action;
}

int TerminalDisplay::motionAfterPasting() { return mMotionAfterPasting; }

void TerminalDisplay::keyPressEvent(QKeyEvent *event) {
    _actSel = 0; // Key stroke implies a screen update, so TerminalDisplay won't
                 // know where the current selection is.

    if (_hasBlinkingCursor) {
        // see TerminalDisplay::setBlinkingCursor
        _blinkCursorTimer->start(std::max(QApplication::cursorFlashTime(), 1000) / 2);
        if (_cursorBlinking)
            blinkCursorEvent();
        else
            _cursorBlinking = false;
    }

    emit keyPressedSignal(event, false);

    event->accept();
}

void TerminalDisplay::inputMethodEvent(QInputMethodEvent *event) {
    QKeyEvent keyEvent(QEvent::KeyPress, 0, Qt::NoModifier,
                                         event->commitString());
    emit keyPressedSignal(&keyEvent, false);

    _inputMethodData.preeditString = event->preeditString().toStdWString();
    update(preeditRect() | _inputMethodData.previousPreeditRect);

    event->accept();
}

QVariant TerminalDisplay::inputMethodQuery(Qt::InputMethodQuery query) const {
    const QPoint cursorPos =
            _screenWindow ? _screenWindow->cursorPosition() : QPoint(0, 0);
    switch (query) {
    case Qt::ImCursorRectangle:
        return imageToWidget(QRect(cursorPos.x(), cursorPos.y(), 1, 1));
        break;
    case Qt::ImFont:
        return font();
        break;
    case Qt::ImCursorPosition:
        // return the cursor position within the current line
        return cursorPos.x();
        break;
    case Qt::ImSurroundingText: {
        // return the text from the current line
        QString lineText;
        QTextStream stream(&lineText);
        PlainTextDecoder decoder;
        decoder.begin(&stream);
        decoder.decodeLine(&_image[loc(0, cursorPos.y())], _usedColumns, 0);
        decoder.end();
        return lineText;
    } break;
    case Qt::ImCurrentSelection:
        return QString();
        break;
    case Qt::ImHints:
        return (int)inputMethodHints();
        break;
    default:
        break;
    }

    return QVariant();
}

bool TerminalDisplay::handleShortcutOverrideEvent(QKeyEvent *keyEvent) {
    int modifiers = keyEvent->modifiers();

    //  When a possible shortcut combination is pressed,
    //  emit the overrideShortcutCheck() signal to allow the host
    //  to decide whether the terminal should override it or not.
    if (modifiers != Qt::NoModifier) {
        int modifierCount = 0;
        unsigned int currentModifier = Qt::ShiftModifier;

        while (currentModifier <= Qt::KeypadModifier) {
            if (modifiers & currentModifier)
                modifierCount++;
            currentModifier <<= 1;
        }
        if (modifierCount < 2) {
            bool override = false;
            emit overrideShortcutCheck(keyEvent, override);
            if (override) {
                keyEvent->accept();
                return true;
            }
        }
    }

    // Override any of the following shortcuts because
    // they are needed by the terminal
    int keyCode = keyEvent->key() | modifiers;
    switch (keyCode) {
    // list is taken from the QLineEdit::event() code
    case Qt::Key_Tab:
    case Qt::Key_Delete:
    case Qt::Key_Home:
    case Qt::Key_End:
    case Qt::Key_Backspace:
    case Qt::Key_Left:
    case Qt::Key_Right:
    case Qt::Key_Escape:
        keyEvent->accept();
        return true;
    }
    return false;
}

bool TerminalDisplay::event(QEvent *event) {
    bool eventHandled = false;
    switch (event->type()) {
    case QEvent::ShortcutOverride:
        eventHandled = handleShortcutOverrideEvent((QKeyEvent *)event);
        break;
    case QEvent::PaletteChange:
    case QEvent::ApplicationPaletteChange:
        _scrollBar->setPalette(QApplication::palette());
        break;
    default:
        break;
    }
    return eventHandled ? true : QWidget::event(event);
}

void TerminalDisplay::setBellMode(int mode) { _bellMode = mode; }

void TerminalDisplay::enableBell() { _allowBell = true; }

void TerminalDisplay::bell() {
    if (_bellMode == NoBell)
        return;

    // limit the rate at which bells can occur
    //...mainly for sound effects where rapid bells in sequence
    // produce a horrible noise
    if (_allowBell) {
        _allowBell = false;
        QTimer::singleShot(500, this, &TerminalDisplay::enableBell);

        if (_bellMode == SystemBeepBell) {
            QApplication::beep();
        } else if (_bellMode == NotifyBell) {
            emit notifyBell();
        } else if (_bellMode == VisualBell) {
            swapColorTable();
            QTimer::singleShot(200, this, &TerminalDisplay::swapColorTable);
        }
    }
}

void TerminalDisplay::selectionChanged() {
    emit copyAvailable(_screenWindow->selectedText(false).isEmpty() == false);
}

void TerminalDisplay::swapColorTable() {
    ColorEntry color = _colorTable[1];
    _colorTable[1] = _colorTable[0];
    _colorTable[0] = color;
    _colorsInverted = !_colorsInverted;
    update();
}

void TerminalDisplay::clearImage() {
    // We initialize _image[_imageSize] too. See makeImage()
    for (int i = 0; i <= _imageSize; i++) {
        _image[i].character = ' ';
        _image[i].foregroundColor =
                CharacterColor(COLOR_SPACE_DEFAULT, DEFAULT_FORE_COLOR);
        _image[i].backgroundColor =
                CharacterColor(COLOR_SPACE_DEFAULT, DEFAULT_BACK_COLOR);
        _image[i].rendition = DEFAULT_RENDITION;
    }
}

void TerminalDisplay::calcGeometry() {
    _scrollBar->resize(_scrollBar->sizeHint().width(), contentsRect().height());
    int scrollBarWidth = _scrollBar->style()->styleHint(
                        QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar)
                        ? 0
                        : _scrollBar->width();
    switch (_scrollbarLocation) {
    case QTermWidget::NoScrollBar:
        _leftMargin = _leftBaseMargin;
        _contentWidth = contentsRect().width() - 2 * _leftBaseMargin;
        break;
    case QTermWidget::ScrollBarLeft:
        _leftMargin = _leftBaseMargin + scrollBarWidth;
        _contentWidth =
                contentsRect().width() - 2 * _leftBaseMargin - scrollBarWidth;
        _scrollBar->move(contentsRect().topLeft());
        break;
    case QTermWidget::ScrollBarRight:
        _leftMargin = _leftBaseMargin;
        _contentWidth =
                contentsRect().width() - 2 * _leftBaseMargin - scrollBarWidth;
        _scrollBar->move(contentsRect().topRight() -
                                         QPoint(_scrollBar->width() - 1, 0));
        break;
    }

    _topMargin = _topBaseMargin;
    _contentHeight =
            contentsRect().height() - 2 * _topBaseMargin + /* mysterious */ 1;

    if (!_isFixedSize) {
        // ensure that display is always at least one column wide
        _columns = qMax(1, _contentWidth / _fontWidth);
        _usedColumns = qMin(_usedColumns, _columns);

        // ensure that display is always at least one line high
        _lines = qMax(1, _contentHeight / _fontHeight);
        _usedLines = qMin(_usedLines, _lines);
    }
}

void TerminalDisplay::makeImage() {
    calcGeometry();

    // confirm that array will be of non-zero size, since the painting code
    // assumes a non-zero array length
    Q_ASSERT(_lines > 0 && _columns > 0);
    Q_ASSERT(_usedLines <= _lines && _usedColumns <= _columns);

    _imageSize = _lines * _columns;

    // We over-commit one character so that we can be more relaxed in dealing with
    // certain boundary conditions: _image[_imageSize] is a valid but unused
    // position
    _image = new Character[_imageSize + 1];

    clearImage();
}

// calculate the needed size, this must be synced with calcGeometry()
void TerminalDisplay::setSize(int columns, int lines) {
    int scrollBarWidth =
            (_scrollBar->isHidden() ||
             _scrollBar->style()->styleHint(QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
                    ? 0
                    : _scrollBar->sizeHint().width();
    int horizontalMargin = 2 * _leftBaseMargin;
    int verticalMargin = 2 * _topBaseMargin;

    QSize newSize =
            QSize(horizontalMargin + scrollBarWidth + (columns * _fontWidth),
                        verticalMargin + (lines * _fontHeight));

    if (newSize != size()) {
        _size = newSize;
        updateGeometry();
    }
}

void TerminalDisplay::setFixedSize(int cols, int lins) {
    _isFixedSize = true;

    // ensure that display is at least one line by one column in size
    _columns = qMax(1, cols);
    _lines = qMax(1, lins);
    _usedColumns = qMin(_usedColumns, _columns);
    _usedLines = qMin(_usedLines, _lines);

    if (_image) {
        delete[] _image;
        makeImage();
    }
    setSize(cols, lins);
    QWidget::setFixedSize(_size);
}

QSize TerminalDisplay::sizeHint() const { return _size; }

void TerminalDisplay::dragEnterEvent(QDragEnterEvent *event) {
    if (event->mimeData()->hasFormat(QLatin1String("text/plain")))
        event->acceptProposedAction();
    if (event->mimeData()->urls().count())
        event->acceptProposedAction();
}

void TerminalDisplay::dropEvent(QDropEvent *event) {
    // KUrl::List urls = KUrl::List::fromMimeData(event->mimeData());
    QList<QUrl> urls = event->mimeData()->urls();

    QString dropText;
    if (!urls.isEmpty()) {
        // TODO/FIXME: escape or quote pasted things if necessary...
        qDebug() << "TerminalDisplay: handling urls. It can be broken. Report any "
                                "errors, please";
        for (int i = 0; i < urls.count(); i++) {
            // KUrl url = KIO::NetAccess::mostLocalUrl( urls[i] , 0 );
            QUrl url = urls[i];

            QString urlText;

            if (url.isLocalFile())
                urlText = url.path();
            else
                urlText = url.toString();

            // in future it may be useful to be able to insert file names with
            // drag-and-drop without quoting them (this only affects paths with spaces
            // in)
            // urlText = KShell::quoteArg(urlText);

            QChar q(QLatin1Char('\''));
            dropText += q + QString(urlText).replace(q, QLatin1String("'\\''")) + q;
            dropText += QLatin1Char(' ');
        }
    } else {
        dropText = event->mimeData()->text();

        dropText.replace(QLatin1String("\r\n"), QLatin1String("\n"));
        dropText.replace(QLatin1Char('\n'), QLatin1Char('\r'));
        if (_trimPastedTrailingNewlines) {
            dropText.replace(QRegularExpression(QStringLiteral("\\r+$")), QString());
        }
        if (_confirmMultilinePaste && dropText.contains(QLatin1Char('\r'))) {
            if (!multilineConfirmation(dropText)) {
                return;
            }
        }
    }

    emit sendStringToEmu(dropText.toLocal8Bit().constData());
}

void TerminalDisplay::doDrag() {
    dragInfo.state = diDragging;
    dragInfo.dragObject = new QDrag(this);
    QMimeData *mimeData = new QMimeData;
    mimeData->setText(QApplication::clipboard()->text(QClipboard::Selection));
    dragInfo.dragObject->setMimeData(mimeData);
    dragInfo.dragObject->exec(Qt::CopyAction);
    // Don't delete the QTextDrag object.  Qt will delete it when it's done with
    // it.
}

void TerminalDisplay::outputSuspended(bool suspended) {
    // create the label when this function is first called
    if (!_outputSuspendedLabel) {
        // This label includes a link to an English language website
        // describing the 'flow control' (Xon/Xoff) feature found in almost
        // all terminal emulators.
        // If there isn't a suitable article available in the target language the
        // link can simply be removed.
        _outputSuspendedLabel = new QLabel(
                tr("<qt>Output has been "
                     "<a href=\"http://en.wikipedia.org/wiki/Flow_control\">suspended</a>"
                     " by pressing Ctrl+S."
                     "  Press <b>Ctrl+Q</b> to resume.</qt>"),
                this);

        QPalette palette(_outputSuspendedLabel->palette());
        // KColorScheme::adjustBackground(palette,KColorScheme::NeutralBackground);
        _outputSuspendedLabel->setPalette(palette);
        _outputSuspendedLabel->setAutoFillBackground(true);
        _outputSuspendedLabel->setBackgroundRole(QPalette::Base);
        _outputSuspendedLabel->setFont(QApplication::font());
        _outputSuspendedLabel->setContentsMargins(5, 5, 5, 5);

        // enable activation of "Xon/Xoff" link in label
        _outputSuspendedLabel->setTextInteractionFlags(
                Qt::LinksAccessibleByMouse | Qt::LinksAccessibleByKeyboard);
        _outputSuspendedLabel->setOpenExternalLinks(true);
        _outputSuspendedLabel->setVisible(false);

        _gridLayout->addWidget(_outputSuspendedLabel);
        _gridLayout->addItem(
                new QSpacerItem(0, 0, QSizePolicy::Expanding, QSizePolicy::Expanding),
                1, 0);
    }

    _outputSuspendedLabel->setVisible(suspended);
}

uint TerminalDisplay::lineSpacing() const { return _lineSpacing; }

void TerminalDisplay::setLineSpacing(uint i) {
    _lineSpacing = i;
    setVTFont(font()); // Trigger an update.
}

int TerminalDisplay::margin() const { return _topBaseMargin; }

void TerminalDisplay::setMargin(int i) {
    _topBaseMargin = i;
    _leftBaseMargin = i;
}

int TerminalDisplay::getCursorX() const {
    return _screenWindow.isNull() ? 0 : _screenWindow->getCursorX();
}

int TerminalDisplay::getCursorY() const {
    return _screenWindow.isNull() ? 0 : _screenWindow->getCursorY();
}

void TerminalDisplay::setCursorX(int x) {
    if (!_screenWindow.isNull())
        _screenWindow->setCursorX(x);
}

void TerminalDisplay::setCursorY(int y) {
    if (!_screenWindow.isNull())
        _screenWindow->setCursorY(y);
}

QString TerminalDisplay::screenGet(int row1, int col1, int row2, int col2, int mode) {
    return _screenWindow.isNull()
                         ? QString()
                         : _screenWindow->getScreenText(row1, col1, row2, col2, mode);
}

AutoScrollHandler::AutoScrollHandler(QWidget *parent)
        : QObject(parent), _timerId(0) {
    parent->installEventFilter(this);
}
void AutoScrollHandler::timerEvent(QTimerEvent *event) {
    if (event->timerId() != _timerId)
        return;

    QMouseEvent mouseEvent(
            QEvent::MouseMove, widget()->mapFromGlobal(QCursor::pos()),
            QCursor::pos(), Qt::NoButton, Qt::LeftButton, Qt::NoModifier);

    QApplication::sendEvent(widget(), &mouseEvent);
}
bool AutoScrollHandler::eventFilter(QObject *watched, QEvent *event) {
    Q_ASSERT(watched == parent());
    Q_UNUSED(watched);

    QMouseEvent *mouseEvent = (QMouseEvent *)event;
    switch (event->type()) {
    case QEvent::MouseMove: {
        bool mouseInWidget = widget()->rect().contains(mouseEvent->pos());

        if (mouseInWidget) {
            if (_timerId)
                killTimer(_timerId);
            _timerId = 0;
        } else {
            if (!_timerId && (mouseEvent->buttons() & Qt::LeftButton))
                _timerId = startTimer(100);
        }
        break;
    }
    case QEvent::MouseButtonRelease:
        if (_timerId && (mouseEvent->buttons() & ~Qt::LeftButton)) {
            killTimer(_timerId);
            _timerId = 0;
        }
        break;
    default:
        break;
    };

    return false;
}

ScrollBar::ScrollBar(QWidget* parent) : QScrollBar(parent) {}

void ScrollBar::enterEvent(QEnterEvent* event)
{
  // show the mouse cursor that was auto-hidden
  if (gs_deadSpot.x() > -1)
  {
    gs_deadSpot = QPoint(-1,-1);
    QApplication::restoreOverrideCursor();
  }
  QScrollBar::enterEvent(event);
}
